This is the first step in a cascade of reactions which results in three possible outcomes: (1) C3b serves as an opsonin which increases phagocytosis; (2) C5a contributes to the inflammation process by attracting phagocytic cells to the cite of infection; and (3) the membrane attack complex (MAC), which is able to create pores in the cell membrane, leading to cell lysis and death, self assembles (Holland and Lambris, 2002). The gene discussed is C3; the disease is infection.