Coagulation factor IX (IPR035694)

Short name: Coagulation_factor_IX

Overlapping homologous superfamilies


Family relationships


Coagulation factor IX (also known as Christmas factor, factor IX or FIX) is a vitamin K-dependent blood coagulation factor involved in the intrinsic blood coagulation pathway. Factor IX is activated (becoming Factor IXa or FIXa) by Factor XIa (or by the Factor VIIa/tissue factor complex). Factor IXa then subsequently activates Factor X in the presence of calcium ions, phospholipids and Factor VIIIa [PMID: 11736930].

FIX deficiency causes haemophilia B (also known as Christmas disease) [PMID: 28243977].

GO terms

Biological Process

GO:0007596 blood coagulation

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.