. "Authored: D'Eustachio, P, 2004-08-24 14:00:00"^^ . "Factor VIIa, bound to tissue factor at the endothelial cell surface (the \"extrinsic tenase complex\"), catalyzes the formation of activated factor X with high efficiency. The amino terminal part of the heavy chain of factor X, the factor X activation peptide, is released. (This peptide has no known function.)"^^ . . . . . . . . "activation of factor X by TF:F7a"^^ . "factor X -> factor Xa + factor X activation peptide (TF:F7a catalyst)"^^ . "3.4.21"^^ . . . . . .