Tissue factor pathway inhibitor 2 (TFPI2)

Tissue factor pathway inhibitor 2 (TFPI2) is a 32 kDa secreted protein belonging to the Kunitz-type family of serine protease inhibitors, structurally composed of three tandem Kunitz domains and a basic C-terminal tail. Unlike the related protein TFPI, TFPI2 is a weak inhibitor of factor VIIa-tissue factor complex and factor Xa but potently inhibits a broad spectrum of other serine proteases, particularly those involved in extracellular matrix turnover such as plasmin, trypsin, and plasma kallikrein. TFPI2 is highly expressed in placenta and a range of other tissues, and its levels are increased in pregnancy. It localizes primarily to the extracellular matrix, where it regulates tissue remodeling, angiogenesis, and cell migration by controlling proteolytic activity. TFPI2 plays a significant role as a tumor suppressor, with loss of expression reported in multiple cancers due to promoter methylation; restoration of expression can inhibit tumor growth, invasion, and metastasis. Additionally, it is implicated in vascular biology, chronic inflammation, and regulation of retinal pigment epithelial cell growth. No approved drugs directly target TFPI2, but it is being explored as a candidate for biomarker development and gene therapy in oncology.

Other names

TFPI-2Placental protein 5 (PP5)Retinal pigment epithelium cell factor 1 (REF1)Placental protein 5REF1PP5

Experimental: gene transfer/epigenetic modulation to increase TFPI2 expression in tumors suppresses growth/metastasis by inhibiting proteases needed for tissue invasion/remodeling. Indirect inhibition of serine proteinases in the tumor microenvironment.