Review question	Which endometrial biomarkers are unlikely to serve as a basis for a diagnostic test for endometriosis?
Importance	Biomarkers that did not show differential expression in women with and without endometriosis are unlikely to be helpful in a diagnostic sense and hence are not worth pursuing. These findings are based on adequately designed studies that met inclusion criteria for this review.
Patients	Reproductive‐aged women with suspected endometriosis or persistent ovarian mass, or women undergoing infertility work‐up
Settings	Hospitals (public or private of any level), outpatient clinics (general gynaecology, reproductive medicine, pelvic pain) or radiology departments
Reference standard	Visualisation of endometriosis at surgery (laparoscopy or laparotomy) with or without histological confirmation
Study design	Cross‐sectional, single gate design (N = 11) or two‐gate design (N = 18); unable to determine if single‐ or two‐gate design for 2 studies. Prospective enrolment; a study could assess more than 1 test or more than 1 type of endometriosis
Risk of bias	Overall judgement	Poor quality (no studies had 'low risk' assessment in all 4 domains)
	Patient selection bias	High risk: 29 studies; unclear risk: 2 studies; low risk: 0 studies
	Index test interpretation bias	High risk: 28 studies; unclear risk: 3 studies; low risk: 0 studies
	Reference standard interpretation bias	High risk: 0 studies; unclear risk: 13 studies; low risk: 18 studies
	Flow and timing selection bias	High risk: 12 studies; unclear risk: 2 studies; low risk: 17 studies
Applicability concerns	Concerns regarding patient selection	High concern ‐ 25 studies; unclear concern ‐ 3 studies; low concern ‐ 3 studies
	Concerns regarding index test	High concern ‐ 0 studies; unclear concern ‐ 0 studies; low concern ‐ 31 studies
	Concerns regarding reference standard	High concern ‐ 0 studies; unclear concern ‐ 0 studies; low concern ‐ 31 studies
Biomarker	Expression levels	rASRM stage	Menstrual cycle phase	Sample collection method	Reference
1. Angiogenesis and growth factors and their receptors
EGF mRNA (epidermal growth factor)	Endometriosis (N = 35)a: 0.13 ± 0.01 Controls (N = 31): 0.24 ± 0.02; P = 0.120 # sub‐analysis per cycle phase ‐ similar findings	III‐IV	Proliferative/secretory	'Endometrial curettage' ‐ likely sharp	Lee 2007
FGF‐2 mRNA (fibroblast growth factor‐2)	Endometriosis (N = 35)a: 17.38 ± 1.73 Controls (N = 31): 20.0 ± 2.53; P = 0.572 # sub‐analysis per cycle phase ‐ similar findings	III‐IV	Proliferative/secretory	'Endometrial curettage' ‐ likely sharp	Lee 2007
Glycodelin mRNA (PP14 or PAEP) (placental protein 14 or progestogen‐associated endometrial protein)	Endometriosis (N = 17)a: 2.5 (0.6‐4.5) Controls (N = 10): 0.936 (0.1‐1.9); P = NS	II‐IV	Proliferative	Sharp curettage	Meola 2009
PDGF‐A mRNA (platelet‐derived growth factor A)	Endometriosis (N = 35)a: 6.52 ± 0.58 Controls (N = 31): 13.02 ± 1.60; P = 0.572 # sub‐analysis per cycle phase ‐ similar findings	III‐IV	Proliferative/secretory	'Endometrial curettage' ‐ likely sharp	Lee 2007
PIGF (placental growth factor)	Endometriosis (N = 18)a: 120 ± 31 Controls (N = 23): 87 ± 16; P = NS Endometriosis (N = 22)a: 87 ± 30 Controls (N = 27): 109 ± 15; P = NS	III‐IV	Proliferative Secretory	Aspiration curettage	Gilabert‐Estelles 2007
PIGF mRNA (placental growth factor)	Endometriosis (N = 18)a: 0.050 ± 0.017 Controls (N = 23): 0.032 ± 0.009 Endometriosis (N = 22)a: 0.037 ± 0.016 Controls (N = 27): 0.024 ± 0.004; P = NS	III‐IV	Proliferative Secretory	Aspiration curettage	Gilabert‐Estelles 2007
PKR1 mRNA (prokineticin receptor 1), EG‐VEGF receptor	Endometriosis (N = 9)b: 1.89 (0.1–5.5) Controls (N = 14): 3.92 (0.0–23.4); P = NS Endometriosis (N = 6)b: 0.43 (0–2.1) Controls (N = 19): 0.64 (0.0–6.7); P = NS	—	Proliferative Secretory	Aspiration curettage	Lee 2010
PKR2 mRNA (prokineticin receptor 2), EG‐VEGF receptor	Endometriosis (N = 9)b: 0.93 (0.0–10.7) Controls (N = 14): 0.75 (0.0–6.6); P = NS Endometriosis (N = 6)b: 0.24 (0.0–1.2) Controls (N = 19): 0 (0.0–1.0); P = NS	—	Proliferative Secretory	Aspiration curettage	Lee 2010
TSP‐1 (thrombospondin‐1)	Endometriosis (N = 18)a: 313 ± 46 ng/mg Controls (N = 23): 210 ± 27 ng/mg; P = NS Endometriosis (N = 22)a: 413 ± 63 ng/mg Controls (N = 27): 317 ± 42 ng/mg; P = NS	III‐IV	Proliferative Secretory	Aspiration curettage	Gilabert‐Estelles 2007
TSP‐1 (thrombospondin‐1)	Endometriosis (N = 58)a: 140 ± 28 ng/mg Controls (N = 38): 81 ± 16 ng/mg; P = NS Endometriosis (N = 58)a: 69 ± 16 ng/mg Controls (N = 38): 69 ± 13 ng/mg; P = NS	—	Proliferative Secretory	Aspiration curettage	Ramon 2011
TSP‐1 mRNA (thrombospondin‐1)	Endometriosis (N = 18)a: 2.621 ± 0.735 Controls (N = 23): 1.510 ± 0.270; P = NS Endometriosis (N = 22)a: 3.093 ± 0.7002 Controls (N = 27): 2.370 ± 0.910; P = NS	III‐IV	Proliferative Secretory	Aspiration curettage	Gilabert‐Estelles 2007
TSP‐1 mRNA (thrombospondin‐1)	Endometriosis (N = 58)a: 1.79 ± 0.36 Controls (N = 38): 2.36 ± 0.49; P = NS Endometriosis (N = 58)a: 2.65 ± 0.87 Controls (N = 38): 1.52 ± 0.39; P = NS	—	Proliferative Secretory	Aspiration curettage	Ramon 2011
TYMP (thymidine phosphorylase)	Endometriosis (N = 15)b: 11.8 (2.7–38.6) ng/ml Controls (N = 14): 16.8 (1.1–37.6) ng/ml; P = 0.68	III‐IV	Proliferative	Aspiration curettage	Laudanski 2014
VEGF (vascular endothelial growth factor)	Endometriosis (N = 10)b: 0.142 (0.087‐0.943) Controls (N = 7): 0.129 (0.097‐0.837); P = 0.943	II‐IV	Menstrual	Menstrual fluid	Da Silva 2014
VEGF mRNA (vascular endothelial growth factor)	Endometriosis (N = 24)b: 5.83 (2.5‐8.75) Controls (N = 23): 5.01 (1.7‐10.83); P = NS # sub‐analysis per cycle phase ‐ similar findings	III‐IV	Proliferative/secretory	'Endometrial biopsy curette' ‐ not specified	Cho 2012
EG‐VEGF mRNA (endocrine gland‐derived VEGF)	Endometriosis (N = 9)b: 0.04 (2.9 × 10‐4– 0.6) Controls (N = 14): 0.03 (5.2 × 10‐6–1.0); P = NS Endometriosis (N = 6)b: 0.28 (2.0 × 10‐4–5.6) Controls (N = 19): 1.50 (0.0–27.9); P = NS	—	Proliferative Secretory	Aspiration curettage	Lee 2010
VEGF/sFlt (VEGF and soluble fms‐like tyrosine kinase ratio)	Endometriosis (N = 24)b: 1.06 (0.71‐2.59) Controls (N = 23): 0.71 (0.35‐1.06); P = 0.064 # sub‐analysis per cycle phase ‐ similar findings	III‐IV	Proliferative/secretory	'Endometrial biopsy curette' ‐ not specified	Cho 2012
2. Apoptosis markers and regulators
Bax mRNA (BCL2‐associated X protein)	Endometriosis (15)b: 1.22 Controls (N = 30): 1.15; P = NS	I‐IV	Proliferative	Sharp curettage	Zubor 2009
Bcl‐xL (B‐cell lymphoma‐extra large, or BCL2‐like‐1 isoform 1)	Endometriosis (15)b: 1.08 Controls (N = 30): 1.07; P = NS	I‐IV	Proliferative	Sharp curettage	Zubor 2009
Bcl‐xL:Bcl‐xS ratio (ratio B‐cell lymphoma‐extra large/B‐cell lymphoma‐extra small)E	Endometriosis (15)b: 2.63 Controls (N = 30): 5.63; P = 0.2965	I‐IV	Proliferative	Sharp curettage	Zubor 2009
3. Cell adhesion molecules and other matrix‐related proteins
α2β1 integrin	Positively stained menstrual effluent: endometriosis (N = 8)c: 7/8 controls (N = 8): 6/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 8/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1994
α3β1 integrin	Positively stained menstrual effluent: endometriosis (N = 8)c: 7/8 controls (N = 8): 6/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 7/8 controls (N = 8): 7/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1994
α4β1 integrin	Positively stained menstrual effluent: endometriosis (N = 8)c: 2/8 controls (N = 8): 3/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 7/8 controls (N = 8): 5/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1994
α5β1 integrin	Positively stained menstrual effluent: endometriosis (N = 8)c: 7/8 controls (N = 8): 4/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 8/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1994
α6β1 integrin	Positively stained menstrual effluent: endometriosis (N = 8)c: 2/8 controls (N = 8): 3/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 8/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1994
αVβ3 integrin	Positive samples: endometriosis (N = 20)c: 10 (50) infertile controls (N = 20): 8 (40) fertile controls (N = 20): 7 (35); P = NS endometriosis (N = 16)c: 16 (100) infertile controls (N = 16): 16 (100) fertile controls (N = 19): 18 (94.7); P = NS	l‐II	Mid‐secretory Late‐secretory	—	Casals 2012
αVβ5 integrins	Glandular cells H Score: endometriosis (N = 40)b: 0.47 (0.0‐1.0) controls (N = 12): 0.6 (0.3‐0.8); P = 0.460 endometriosis (N = 40)b: 1.2 (0.5‐1.9) controls (N = 12): 1.3 (0.9‐1.7); P = 0.507	I‐IV	Proliferative Secretory	—	Puy 2002
Stromal cells H Score: endometriosis (N = 40)b: 2.0 (1.0‐2.7) controls (N = 12): 1.9 (1.4‐2.5); P = 0.920 endometriosis (N = 40)b: 1.7 (0.8‐2.7) controls (N = 12): 1.5 (1.1‐2.4); P = 0.752	I‐IV	Proliferative Secretory	—	Puy 2002
αVβ6 integrins	Glandular cells H Score : endometriosis (N = 40)b: 0.5 (0.1‐1.3) controls (N = 12): 0.75 (0.3‐1.2); P = 0.856 endometriosis (N = 40)b: 0.7 (0.3‐0.9) controls (N = 12): 1.0 (0.8‐1.2); P = 0.975	I‐IV	Proliferative Secretory	—	Puy 2002
Stromal cells H Score: endometriosis (N = 40)b: 1.4 (0.6‐2.2) controls (N = 12): 1.2 (0.3‐2.5); P = 0.651 endometriosis (N = 40)b: 1.8 (0.8‐2.6) controls (N = 12): 1.7 (1.0‐2.2); P = 0.635	I‐IV	Proliferative Secretory	—	Puy 2002
ICAM1 (intercellular adhesion molecule1)	Endometriosis (N = 8)a: 0.56 ± 0.25 Control (N = 8): 0.69 ± 0.19; P = NS # sub‐analysis per cycle phase ‐ similar findings	I‐IV	Proliferative/secretory	Aspiration curettage	Pino 2009
ICAM1 (CD54) (intercellular adhesion molecule1)	(Small/medium/large cells): endometriosis (N = 10)b: 96 (25–193)/92 (13–106)/106 (18–143) controls (12): 51 (4–453)/48 (5–129)/49 (4–103); P = NS # significant difference between the groups in secretory phase ‐ no data for 2 × 2 table	—	Proliferative	Aspiration curettage	Prefumo 2002
sICAM1 (soluble ICAM1)	Endometriosis (N = 8)a: 0.31 ± 0.16 Control (N = 8): 0.13 ± 0.13; P = NS # sub‐analysis per cycle phase ‐ similar findings	I‐IV	Proliferative/secretory	Aspiration curettage	Pino 2009
ICAM1 mRNA (intercellular adhesion molecule1)	Endometriosis (N = 6)a: 0.44 ± 0.11 Control (N = 6): 0.76 ± 0.11; P = NS	I‐IV	Proliferative/secretory	Aspiration curettage	Pino 2009
E‐cadherin	Positively stained menstrual effluent: endometriosis (N = 8)c: 3/8 controls (N = 8): 3/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 8/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1994
LAMA5 (laminin subunit alpha‐5)	Endometriosis (N = 15)b: 1500 (1060–1840) pg/ml controls (N = 14):1400 (1340–1780) pg/ml; P = 0.95	III‐IV	Proliferative	Aspiration curettage	Laudanski 2014
LFA‐3 (CD58) (leukocyte function associated molecule‐3)	(Small/medium/large cells): endometriosis (N = 10)b: 101 (64 – 302)/108 (28–155)/65 (35–197) controls (12): 315 (65 – 824)/150 (33–264)/124 (67–164); P = NS endometriosis (N = 10)b: 70 (34–252)/49 (26–184)/48 (37–118) controls (12): 171 (145–643)/134 (94–223)/162 (56–228); P = NS	—	Proliferative Secretory	Aspiration curettage	Prefumo 2002
MMP‐1 (matrix metalloproteinase‐1)	Endometriosis (N = 8)a: just above detection limit Control (N = 8): just above detection limit; P = NS	I‐IV	Proliferative/secretory	Aspiration curettage	Pino 2009
MMP‐9 (matrix metalloproteinase‐9)	Endometriosis (N = 8)a: 2.75 ± 1.5 Control (N = 8): 0.75 ± 0.13; P = NS # sub‐analysis per cycle phase ‐ similar findings	I‐IV	Proliferative/secretory	Aspiration curettage	Pino 2009
MMP‐9 mRNA (matrix metalloproteinase‐9)	Endometriosis (N = 6)a: 0.21 ± 0.06 Control (N = 6): 0.33 ± 0.07; P = NS	I‐IV	Proliferative/secretory	Aspiration curettage	Pino 2009
OPN (osteopontin)	Positive samples: endometriosis (N = 20)c: 14 (70) infertile controls (N = 20): 13 (65) fertile controls (N = 20): 14 (70); P = NS endometriosis (N = 16)c: 16 (100) infertile controls (N = 16): 16 (100) fertile controls (N = 19): 19 (100); P = NS	I‐II	Mid‐secretory Late‐secretory	—	Casals 2012
OPN (+)/αVβ3 (+)	Positive samples: endometriosis (N = 20)c: 8 (40) infertile controls (N = 20): 7 (35) fertile controls (N = 20): 6 (30); P = NS endometriosis (N = 16)c: 16 (100) infertile controls (N = 16): 16 (100) fertile controls (N = 19): 18 (94.7); P = NS	I‐II	Mid‐secretory Late‐secretory	—	Casals 2012
PAI‐1 (plasminogen activator inhibitor ‐ 1)	Antigenic levels: endometriosis (N = 21)a: 0.46 ± 0.18 ng/mg controls (N = 35): 0.73 ± 0.19 ng/mg; P = NS Functional levels: endometriosis (N = 21)a: 1.64 ± 0.59 U/mg controls (N = 35): 1.12 ± 0.35 U/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
PAI‐1 (plasminogen activator inhibitor ‐ 1)	Endometriosis (N = 18)a: 1.73 ± 0.56 ng/mg Controls (N = 23): 1.48 ± 0.40 ng/mg Endometriosis (N = 22)a: 2.51 ± 0.65 ng/mg Controls (N = 27): 1.44 ± 0.44 ng/mg; P = NS	III‐IV	Proliferative Secretory	Aspiration curettage	Gilabert‐Estelles 2007
PAI‐1 mRNA (gene encoding for (plasminogen activator inhibitor ‐ 1)	Endometriosis (N = 18)a: 0.197 ± 0.068 Controls (N = 23): 0.117 ± 0.030 Endometriosis (N = 22)a: 0.496 ± 0.158 Controls (N = 27): 0.131 ± 0.041; P = NS	III‐IV	Proliferative Secretory	Aspiration curettage	Gilabert‐Estelles 2007
PAI‐2 (plasminogen activator inhibitor ‐ 2)	Antigenic levels: endometriosis (N = 21)a: 10.69 ± 3.33 ng/mg controls (N = 35): 4.53 ± 1.75 ng/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
PAI‐3 (plasminogen activator inhibitor ‐ 3)	Antigenic levels: endometriosis (N = 21)a: 233 ± 50 ng/mg controls (N = 35): 340 ± 45 ng/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
tPA (tissue‐type plasminogen activator)	Antigenic levels: endometriosis (N = 21)a: 12.69 ± 1.52 ng/mg controls (N = 35): 9.14 ± 1.33 ng/mg; P = NS Functional levels: endometriosis (N = 21)a: 0.41 ± 0.09 U/mg controls (N = 35): 0.58 ± 0.10 U/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
uPA (urokinase‐type plasminogen activator)	Functional levels: endometriosis (N = 21)a: 0.11 ± 0.02 ng/mg controls (N = 35): 0.06 ± 0.01 ng/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
uPA‐R (urokinase‐type plasminogen activator receptor)	Antigenic levels: endometriosis (N = 21)a: 2.51 ± 0.55 ng/mg controls (N = 35): 2.90 ± 0.32 ng/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
tPA‐PAI‐3 (tissue plasminogen activator and plasminogen activator inhibitor ‐ 3 complex)	Antigenic levels: endometriosis (N = 21)a: 0.20 ± 0.10 ng/mg controls (N = 35): 0.06 ± 0.02 ng/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
uPA‐PAI‐3 (urokinase plasminogen activator and plasminogen activator inhibitor ‐ 3 complex)	Antigenic levels: endometriosis (N = 21)a: 0.27 ± 0.13 ng/mg controls (N = 35): 0.36 ± 0.18 ng/mg; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
TIMP‐1 protein (tissue inhibitor of metalloproteinases‐1)	Endometriosis (N = 45)b: 0.253 ± 0.018 controls (N = 15): 0.267 ± 0.010; P = NS	II‐IV	Proliferative/secretory	—	Chen 2004
Endometriosis (N = 21)a: 31± 6 ng/ml controls (N = 35): 30 ± 5 ng/ml; P = NS	III‐IV	Menstrual/proliferative/secretory	—	Gilabert‐Estelles 2003
Endometriosis (N = 15)b: 56.7 (13.5–213.5) ng/ml Controls (N = 14): 58 (36.2–187.8) ng/ml; P = 0.45	III‐IV	Proliferative	Aspiration curettage	Laudanski 2014
TIMP‐1 mRNA (tissue inhibitor of metalloproteinases‐1)	Endometriosis (N = 18)a: 1.190 ± 0.228 Controls (N = 23): 1.589 ± 0.335 Endometriosis (N = 22)a: 2.028 ± 0.392 Controls (N = 27): 1.506 ± 0.363; P = NS	III‐IV	Proliferative Secretory	Aspiration curettage	Gilabert‐Estelles 2007
Endometriosis (N = 35)b: 2.31 ± 1.21 Controls (N = 20): 2.40 ± 0.89; P = NS	I‐IV	Proliferative/secretory	'Endometrial curettage' ‐ not specified	Li 2006
VCAM‐1 (CD106) (vascular cell adhesion molecule‐1)	(Small/medium/large cells): endometriosis (N = 10)b: 8 (0–42)/3 (2–22)/43 (0–57) controls (12): 34 (0–60)/14 (0–24)/21 (0–64); P = NS endometriosis (N = 10)b: 28 (5–64)/22 (6–60)/18 (10–126) controls (12): 27 (5–130)/18 (3–62)/33 (13–238); P = NS	—	Proliferative Secretory	Aspiration curettage	Prefumo 2002
4. Cell cycle regulatory molecules
Cyclin B1 mRNA	Endometriosis (N = 20)b: 0.79 ± 1.08 Controls: (N = 30): 0.51 ± 1.04; P = NS Endometriosis (N = 20)b: 0.98 ± 1.24 Controls (N = 30): 0.50 ± 0.49; P = NS # similar findings were observed for protein expression	II‐III	Proliferative Secretory	—	Tang 2009
Cdc2 mRNA (cyclin dependent kinase‐2)	Endometriosis (N = 20)b: 5.0 ± 5.0 Controls: (N = 30): 5.0 ± 5.0; P = NS Endometriosis (N = 20)b: 4.5 ± 5.5 Controls (N = 30): 4.5 ± 5.5; P = NS # similar findings were observed for protein expression	II‐III	Proliferative Secretory	—	Tang 2009
Plk1 mRNA (polo‐like kinase‐1)	Endometriosis (N = 20)b: 1.64 ± 1.18 Controls (N = 30): 1.35 ± 0.91; P = NS Endometriosis (N = 20)b: 0.84 ± 1.04 Controls (N = 30): 0.52 ± 0.44; P = NS # similar findings were observed for protein expression	II‐III	Proliferative Secretory	—	Tang 2009
5. Cell proliferation markers
Ki‐67 (Antigen KI‐67 or MKI67, marker of cellular proliferation)	Stromal cells: endometriosis (N = 13)b: 8.4 ± 1.4 controls (N = 6): 10.9 ± 4.8; P = NS endometriosis (N = 12)b: 9.6 ± 1.8 controls (N = 8): 10.5 ± 4.8; P = NS # data for glandular epithelium and blood vessels are also reported ‐ no difference between the groups	II‐III	Proliferative Secretory	Sharp curettage	Bourlev 2006
BW 495/36, endometrial epithelial marker	Positively stained menstrual effluent: endometriosis (N = 8)c: 8/8 controls (N = 8): 6/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 7/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1995
6. Cytoskeleton molecules
cytokeratin 18	Positively stained menstrual effluent: endometriosis (N = 8)c: 8/8 controls (N = 8): 7/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 8/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1995
CK19 or CYFRA 21‐1 (cytokeratin 19)	Positively stained menstrual effluent: endometriosis (N = 8)c: 8/8 controls (N = 8): 7/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 8/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1995
Vimentin	Positively stained menstrual effluent: endometriosis (N = 8)c: 8/8 controls (N = 8): 7/8; P = NS Positively stained endometrium: endometriosis (N = 8)c: 8/8 controls (N = 8): 8/8; P = NS	I	Early proliferative (day 2‐5)	Aspiration curettage	Van der Linden 1995
7. DNA‐repair and telomer maintenance molecules
Telomerase activity (relative telomerase activity (RTA))	Endometriosis (N = 30)b: 17.8 ± 30.8 Controls (N = 30): 7.6 ± 13.2; P = NS	I‐IV	Proliferative/secretory	—	Kim 2007
8. High throughput markers
mRNAome (mRNA microarray)	Endometriosis (N = 31)d: 0 Controls (N = 18): 0	I‐IV	Menstrual/secretory	Aspiration curettage	Fassbender 2012
9. Hormonal markers
EST (oestrogen sulphotransferase)	Glandular cells staining: endometriosis (N = 35)e: strong 2, medium 12, weak 8, absent 25 controls (N = 33): strong 9, medium 8, weak 6, absent 10; P = NS Stromal cells staining: endometriosis (N = 35)e: absent 35 controls (N = 33): absent 33; P = NS	I‐II	Proliferative/secretory	'Endometrial curettage' ‐ likely sharp	Hudelist 2007
LGR7 relaxin receptor mRNA (leucine‐rich G protein‐coupled receptor 7) evaluated to distinguish endometrioma from other non‐malignant ovarian masses	Endometriosis (N = 4)f: 0.95 Controls (N = 7): 1; P = NS Endometriosis (N = 9)f: 1.27 Controls (N = 12): 1; P = NS	III‐IV	Proliferative Secretory	—	Morelli 2010
Relaxin mRNA evaluated to distinguish endometrioma from other non‐malignant ovarian masses	Endometriosis (N = 13)c: 9 (69.2) Control (N = 19): 14 (73.7); P = NS # sub‐analysis per cycle phase ‐ similar findings	III‐IV	Proliferative/secretory	—	Morelli 2010
10. Immune system and inflammatory markers
A Cytokines
LIF (leukaemia‐inhibitory factor)	Endometriosis (N = 14)b: 25.53 (12.63–43.32) pg/ml Controls (N = 21): 36.26 (14.45–59.32); P = NS	I‐II	Secretory	Uterine flushing	Mikolajczyk 2006
LIF mRNA (leukaemia‐inhibitory factor gene)	Endometriosis (N = 14)b: 0.90 (0.73–1.09) Controls (N = 21): 0.92 (0.74–1.56); P = NS	I‐II	Secretory	Aspiration curettage	Mikolajczyk 2006
TNF‐a (tumour necrosis factor‐alpha)	Endometriosis (N = 10)b: 386.4 (48.31‐3636.06) Controls (N = 7): 56.02 (10.42‐619.205); P = 0.219	II‐IV	Menstrual	Menstrual fluid	Da Silva 2014
TNF‐a mRNA (tumour necrosis factor‐alpha)	Endometriosis (N = 25)b: 0.0005 (0.0003–0.0020) Controls (N = 25): 0.0002 (0.0001–0.0007); P = NS	I‐IV	Proliferative/secretory	'Endometrial curettage' ‐ not specified	Chen 2013
B Immune cells: peripheral blood mononuclear cells (PBMC)
CD56+ cells (endometrial granulated lymphocytes)	Early/mid/late secretory phase: endometriosis (N = 16)a: 1120 ± 160/1320 ± 160/2200 ± 240 controls (N = 17): 1200 ± 140/1360 ± 200/2440 ± 200; P = NS	I‐IV	Secretory	—	Klentzeris 1995
CD38+ cells (endometrial granulated lymphocytes)	Early/mid/late secretory phase: endometriosis (N = 16)a: 950 ± 200/1650 ± 300/3000 ± 300 controls (N = 17): 1550 ± 300/1750 ± 350/3000 ± 250; P = NS	I‐IV	Secretory	—	Klentzeris 1995
CD22+ cells (B lymphocytes)	early/mid/late secretory phase: endometriosis (N = 16)a: 87 ± 28/92 ± 31/120 ± 24 controls (N = 17): 90±31/104 ± 39/115 ± 28; P = NS	I‐IV	Secretory	—	Klentzeris 1995
CD68+ cells (macrophages)	Endometriosis (N = 31)b: 216.10 ± 104.41 Controls (N = 29): 175.93 ± 43.05; p = 0.06 # sub‐analysis per cycle phase ‐ significant difference between the groups only in proliferative phase ‐ no data for 2 × 2 table	I‐IV	Any phase	Aspiration curettage	Cetin 2013
CD68+ cells (macrophages)	Early/mid/late secretory phase: endometriosis (N = 16)a: 1178 ± 186/1271 ± 287/1643 ± 248 controls (N = 17): 1054 ± 155/1116 ± 155/1519 ± 287; P = NS	I‐IV	Secretory	—	Klentzeris 1995
CD16+ cells (natural killer cells)	Early/mid/late secretory phase: endometriosis (N = 16)a: 1276 ± 377/1305 ± 290/1421 ± 348 controls (N = 17): 957 ± 348/1044 ± 377/1189 ± 290; P = NS	I‐IV	Secretory	—	Klentzeris 1995
CD8+ cells (T suppressor/cytotoxic lymphocytes)	Early/mid/late secretory phase: endometriosis (N = 16)a: 691 ± 109/855 ± 127/891 ± 91 controls (N = 17): 782 ± 73/891 ± 91/964 ± 91; P = NS	I‐IV	Secretory	—	Klentzeris 1995
CD4+ cells (T helper/inducer lymphocytes)	Early/mid/late secretory phase: endometriosis (N = 16)a: 321 ± 57/357 ± 50/400 ± 64 controls (N = 17): 293 ± 57/307 ± 57/343 ± 57; P = NS	I‐IV	Secretory	—	Klentzeris 1995
C Interleukins
IL‐1β mRNA (interleukin ‐1β)	Endometriosis (N = 25)b: 0.0295 (0.0056–0.1039) Controls (N = 25): 0.008 (0.0040–0.0251); P = NS	I‐IV	Proliferative/secretory	'Endometrial curettage' ‐ not specified	Chen 2013
IL‐11 (interleukin ‐ 11)	Endometriosis (N = 14)b: not detected Controls (N = 21): not detected; P = NS	I‐II	Secretory	Uterine flushing	Mikolajczyk 2006
IL‐11 mRNA (interleukin ‐ 11)	Endometriosis (N = 14)b: 0.48 (0.39–0.59) Controls (N = 21): 0.52 (0.42–0.61); P = NS	I‐II	Secretory	Aspiration curettage	Mikolajczyk 2006
IL‐1R1 mRNA (interleukin ‐1 receptor type II)	Stroma positive samples: endometriosis (N = 17)c: 9 (53) controls (N = 17): 14 (82); P = 0.299 Glandular cells positive samples: endometriosis (N = 16)c: 13 (81) controls (N = 17): 14 (82); P = 0.411 # sub‐analysis per cycle phase ‐ similar findings	I‐II	Proliferative/secretory	—	Lawson 2008
D other immune/inflammatory markers
MPO (myeloperoxidase)	Endometriosis (N = 10)b: 1.229 (0.778‐2.094) Controls (N = 7): 1.69 (0.95‐1.84); P = 0.669	II‐IV	Menstrual	Menstrual fluid	Da Silva 2014
NAG (N‐acetyl‐β‐D‐Glucosaminidase)	Endometriosis (N = 10)b: 723.26 (536.7‐768.73) Controls (N = 7): 663.62 (357.5‐1214.1); P = 1.0	II‐IV	Menstrual	Menstrual fluid	Da Silva 2014
11. Mediators of prostaglandin biosynthesis
Akr1B1 mRNA (aldoketoreductase ‐1B1, PGF2a synthase)	Endometriosis (N = 22)b: 216.9 ± 25.9 Controls (N = 12): 217.6 ± 15.6; P = NS Endometriosis (N = 23)b: 121.2 ± 18.7 Controls (N = 17): 188.3 ± 31.9; P = NS	I‐IV	Proliferative Secretory	—	Rakhila 2013
Akr1C3 mRNA (aldoketoreductase ‐1C3, PGF2a synthase)	Endometriosis (N = 22)b: 132.8 ± 21.1 Controls (N = 12): 127.9 ± 26.5; P = NS Endometriosis (N = 23)b: 185.9 ± 31.1 Controls (N = 17): 196.0 ± 45.9; P = NS	I‐IV	Proliferative Secretory	—	Rakhila 2013
Cox‐1 mRNA (cyclo‐oxygenase‐1)	Endometriosis (N = 22)b: 263.6 ± 103.1 Controls (N = 12): 237.9 ± 78.3; P = NS Endometriosis (N = 23)b: 1045.0 ± 313.8 Controls (N = 17): 564.6 ± 151.2; P = NS	I‐IV	Proliferative Secretory	—	Rakhila 2013
15‐PGDH mRNA (15‐hydroxyprostaglandin dehydrogenase)	Endometriosis (N = 22)b: 41.3 ± 11.4 Controls (N = 12): 18.4 ± 3.2; P = NS Endometriosis (N = 23)b: 77.2 ± 51.4 Controls (N = 17): 48.1 ± 26.8; P = NS	I‐IV	Proliferative Secretory	—	Rakhila 2013
cPGES mRNA (cytosolic PGE2 synthase)	Endometriosis (N = 22)b: 63.6 ± 4.6 Controls (N = 12): 68.3 ± 4.8; P = NS Endometriosis (N = 23)b: 55.2 ± 4.3 Controls (N = 17): 61.4 ± 3.9; P = NS	I‐IV	Proliferative Secretory	—	Rakhila 2013
12. Nerve sheath and nerve growth markers
NF (neurofilament)	Endometriosis (N = 20)b: 0.02 ± 0.10 Controls (N = 20): 0.025 ± 1.04; P = NS	I‐II	Secretory	Aspiration curettage	Bokor 2009
NF (neurofilament)	Endometriosis (N = 31): no staining Controls (N = 29): no staining	I‐IV	Any phase	Aspiration curettage	Cetin 2013
PGP 9.5 (protein gene product 9.5)	Endometriosis (N = 31): no staining Controls (N = 29): no staining	I‐IV	Any phase	Aspiration curettage	Cetin 2013
13. Other peptides and proteins
hBD‐2 mRNA (human b‐defensin‐2)	Endometriosis (N = 25)b: 0.0343 (0.0025–2.0326) Controls (N = 25): 0.0034 (0.0025–0.0424); P = NS	I‐IV	Proliferative/secretory	'Endometrial curettage' ‐ not specified	Chen 2013
hBD‐2 (human b‐defensin‐2)	Negative samples: endometriosis (N = 25)c: 8 (32) controls (N = 25): 10 (40); P = NS	I‐IV	Proliferative/secretory	'Endometrial curettage' ‐ not specified	Chen 2013
14. Transcription factors and signalling molecules
AKT1 (RAC‐alpha serine/threonine‐protein kinase)	Endometriosis (N = 15)b: 7.4 (1.4–15.1) ng/ml Controls (N = 14): 5.6 (1.4–15.4) ng/ml; P = 0.9	III‐IV	Proliferative	Aspiration curettage	Laudanski 2014
JAG1 (jagged 1 protein)	Endometriosis (N = 15)b: 1.5 (0.3–6.5) ng/ml Controls (N = 14): 1.5 (0.4–2.8) ng/ml; P = 0.82	III‐IV	Proliferative	Aspiration curettage	Laudanski 2014
NS = Not stated