C2 and age-related macular degeneration: In addition, complement factor B (CFB) and complement component 2 (C2) [17], complement component 3 (C3) [18], age-related maculopathy susceptibility 2 (ARMS2) [19], apolipoprotein E (APOE) [20, 21] and FGD6 [22] also play an important role in the development of AMD.