<prompt> All endothelial cells produce thrombomodulin except those found inHepatic circulationCutaneous circulationCerebral circulationRenal circulation  <response>: ref Robbins 7e p85, 8e p116 Harrison 17e p365,9e p121 Thrombomodulin functions as a cofactor in the thrombin-induced activation of protein C in the anticoagulant pathway by forming a 1:1 stoichiometric complex with thrombin. This raises the speed of protein C activation thousandfold. Thrombomodulin-bound thrombin has procoagulant effect at the same time by inhibiting fibrinolysis by cleaving thrombin-activatable fibrinolysis inhibitorTAFI, aka carboxypeptidase B2 into its active form. Thrombomodulin is a glycoprotein on the surface of endothelial cells that, in addition to binding thrombin, regulates C3b inactivation by factor I. Mutations in the thrombomodulin gene THBD have also been repoed to be associated with atypical hemolytic-uremic syndrome aHUS Not synthesized by cerebral e aeries cells 