Table 1.

Characteristics of selected biomarkers

Marker	Function	Cancers	References
ALDH1A1	stem-like cells biomarker involved in dehydrogenation of aldehydes to their corresponding carboxylic acids; plays role in differentiation, proliferation and motility	ovarian, breast, head and neck lung colorectal endometrial (ICH study)	Rahadiani et al. [5]
CA9	transmembrane HIF- 1훼-dependent glycoprotein responsible for the regulation of pH in the tumor microenvironment	colorectal, gastric, endometrial	Hynninen P et al. [6], Sadlecki et al. [7]
CD44	hyaluronic acid receptor, responsible for cell adhesion; affects carcinogenesis through cell migration and metastasis initiation; cancer stem cell marker	breast, pancreatic, gastric, hepatocellular, bladder, biliary, vulvar, endometrial (ICH study)	Wojciechowski et al. [8], Elbasateeny et al. [9], Yan et al. [10]
EpCAM	calcium-independent homophilic cell adhesion molecule of 39–42 kDa, frequently and highly expressed on carcinomas, tumor-initiating cells, selected tissue progenitors, and embryonic and adult stem cells	ovarian, breast, uterine serous cancer	El-Sahwi et al. [11], Hsu et al. [12]
Hepsin	a type II transmembrane serine protease originally identified in the human liver as a cDNA clone; Hepsin mRNA is highly expressed in normal liver tissues, while it is poorly expressed in other tissues, including normal kidney, pancreas, lung, thyroid, pituitary gland and testis	prostate, renal, ovarian, endometrial	El-Rebey et al. [13] Matsuo et al. [14]
Kallikrein 6	serine protease with roles in diverse cellular activities, including blood coagulation, wound healing, digestion, and immune responses as well as tumor invasion and metastasis	ovarian, uterine serous cancer	Santin et al. [15] Dorn et al. [16]
L1CAM	a neuronal cell adhesion transmembrane protein with a strong implication in cell migration, adhesion, neurite outgrowth, myelination and neuronal differentiation; plays a role in migration, invasion, growth metastasis and chemoresistance.	ovarian, breast, gastric, melanoma, endometrial, esophageal, colorectal, pancreatic, prostate, neuroblastoma	Bosse et al. [17] Pasanen et al. [18] Zeimet et al. [19] Tangen et al. [20]
Mesothelin	a cell-surface glycoprotein with normal expression limited to mesothelial cells lining the pleura, peritoneum; the biologic role that MSLN plays in these cells remains unclear; in cancer it increases cellular resistance to anoikis, upregulates matrix metalloproteinases important in cellular invasion and metastasis, and induces secretion of autocrine growth factors	malignant mesothelioma, pancreatic, ovarian, lung, endometrial cancer, biliary gastric, pediatric acute myeloid leukemia	Dainty et al. [21] Obulhasim et al. [22]
Midkine	a secreted, heparin-binding growth factor; a 13- kDa protein rich in basic amino acids and cysteine; is highly expressed during embryo- genesis; in the adult, the highest transcript levels are in the intestine with low levels in the cerebellum, thyroid, kidney, bladder, lung alveoli, colon, stomach, and spleen; has a role in oncogenic transformation of fibroblasts, antiapoptotic activity, and angiogenic activity	breast, lung, esophagus, colon, ovary, urinary bladder, and prostate, glioblastoma, neuroblastoma, Wilms’ tumor	Tanabe et al. [23]
TGM2	predominantly a cytosolic protein, also present in the nucleus, plasma membrane and in the extracellular environment; a marker of cancer development and cancer stem cell-survival	ovarian, breast, pancreatic, prostate, glioma, melanoma, lung, colon, leukemia	Li et al. [24] Eckert et al. [25]