TFPI

Tissue factor pathway inhibitor (or TFPI) is a single-chain polypeptide which can reversibly inhibit Factor Xa (Xa). While Xa is inhibited, the Xa-TFPI complex can subsequently also inhibit the FVIIa-TF complex. TFPI contributes significantly to the inhibition of Xa in vivo, despite being present at concentrations of only 2.5nM.
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