Tissue factor
（重定向自Coagulation factor III）
Tissue factor, also called platelet tissue factor, factor III, thromboplastin, or CD142 is a protein present in subendothelial tissue and leukocytes necessary for the initiation of thrombin formation from the zymogen prothrombin. Thromboplastin defines the cascade that leads to the activation of factor X - the tissue factor pathway. In doing so it has replaced the previously named extrinsic pathway in order to eliminate ambiguity.