Table 1.

Function and dysfunction of human serpins

Serpin	Alternative name(s)	Protease target or function	Involvement in disease
SERPINA1	Antitrypsin	Extracellular; inhibition of neutrophil elastase	Deficiency results in emphysema: polymerization and retention in the ER results in cirrhosis [14,64,65]
SERPINA2	Antitrypsin-related protein	Not characterized, probable pseudogene
SERPINA3	Antichymotrypsin	Extracellular; inhibition of cathepsin G	Deficiency results in emphysema (see [61] for a review)
SERPINA4	Kallistatin (PI4)	Extracellular, inhibition of kallikrein [68]
SERPINA5	Protein C inhibitor (PAI-3)	Extracellular; inhibition of active protein C (see [69] for a review)	Angioedema
SERPINA6	Corticosteroid-binding globulin	Extracellular; non-inhibitory; cortisol binding	Deficiency linked to chronic fatigue [83,84]
SERPINA7	Thyroxine-binding globulin	Extracellular; non-inhibitory, thyroxine binding	Deficiency results in hypothyroidism [85]
SERPINA8	Angiotensinogen	Extracellular; non-inhibitory; amino-terminal cleavage by the protease renin results in release of the decapeptide angiotensin I	Certain variants linked to essential hypertension [86]
SERPINA9	Centerin	Extracellular; maintenance of naive B cells [70]
SERPINA10	Protein Z-dependent proteinase inhibitor	Extracellular; inhibition of activated factor Z and XI	Deficiency linked to venous thromboembolic disease [87]
SERPINA11	XP_170754.3	Not characterized
SERPINA12	Vaspin	Extracellular; insulin-sensitizing adipocytokine [71]
SERPINA13	XM_370772	Not characterized
SERPINB1	Monocyte neutrophil elastase inhibitor	Intracellular; inhibition of neutrophil elastase [72]
SERPINB2	Plasminogen activator inhibitor-2 (PAI2)	Intracellular; inhibition of uPA (see [73] for a review)
SERPINB3	Squamous cell carcinoma antigen-1	Intracellular; cross-class inhibition of cathepsins L and V [6]
SERPINB4	Squamous cell carcinoma antigen-2	Intracellular; cross-class inhibition of cathepsin G and chymase [74]
SERPINB5	Maspin	Intracellular; non-inhibitory; inhibition of metastasis through uncharacterized mechanism	Downregulation and/or intracellular location linked to tumor progression and overall prognosis [10]
SERPINB6	Proteinase inhibitor-6 (PI6)	Intracellular, inhibition of cathepsin G [75]
SERPINB7	Megsin	Intracellular; megakaryocyte maturation [76]	IgA nephropathy
SERPINB8	Cytoplasmic antiproteinase 8 (PI8)	Intracellular; inhibition of furin [77]
SERPINB9	Cytoplasmic antiproteinase 9 (PI9)	Intracellular, inhibition of granzyme B [78]
SERPINB10	Bomapin (PI10)	Intracellular; inhibition of thrombin and trypsin [79]
SERPINB11	Epipin	Intracellular
SERPINB12	Yukopin	Intracellular; inhibition of trypsin [80]
SERPINB13	Headpin (PI13)	Intracellular; inhibition of cathepsins L and K
SERPINC1	Antithrombin	Extracellular; thrombin and factor Xa inhibitor	Deficiency results in thrombosis (see [88] for review)
SERPIND1	Heparin cofactor II	Extracellular; thrombin inhibitor	May contribute to thrombotic risk when combined with other deficiencies [89]
SERPINE1	Plasminogen activator inhibitor I (PAI1)	Extracellular; inhibitor of thrombin, uPA, tPA and plasmin	Abnormal bleeding [90]
SERPINE2	Protease nexin I (PI7)	Extracellular; inhibition of uPA and tPA
SERPINE3	Hs.512272	Not characterized
SERPINF1	Pigment epithelium derived factor	Non-inhibitory; potent anti-angiogenic molecule [81]
SERPINF2	Alpha-2-antiplasmin	Extracellular; plasmin inhibitor	Unrestrained fibrinolytic activity, bleeding [91]
SERPING1	C1 inhibitor	C1 esterase inhibitor	Angioedema [92]
SERPINH1	47kDa heat-shock protein	Non-inhibitory molecular Chaperone for collagens [9]
SERPINI1	Neuroserpin (PI12)	Extracellular; inhibitor of tPA, uPA and plasmin	Polymerization results in dementia [17]
SERPINI2	Myoepithelium-derived serine proteinase inhibitor (PI14)	Extracellular; inhibition of cancer metastasis [82]