Complement C5 is part of the terminal sequence in the complement pathway. In particular, it is cleaved into C5a and C5b which are responsible for chemotaxis, inflammation, and initiating the formation of the membrane attack complex (MAC). Drugs that inhibit complement C5 have been used in Paroxysmal nocturnal hemoglobinuria (PNH) patients to lessen thrombotic complications by lessening intravascular hemolysis.
