C5 and Venous thrombosis: Later experiments in C3-/- and C5-/- mice showed that deficiency of anaphylatoxins C3 and C5 have different effects on thrombus formation: C3 deficiency reduces platelet activation, while C5 deficiency impairs TF- and myeloid cell-dependent fibrin formation in venous thrombosis and does not affect platelet activation [61,591].