C3 and age-related macular degeneration: Several lines of supporting evidence include (1) the presence of complement components in the choriocapillaris and the retina, especially in drusen [14–16, 75]; (2) increased MAC in the choriocapillaris of AMD patients [18]; and (3) the genetic association of C2, C3, CFB, CFI, and the regulator of complement activation (RCA) gene cluster on 1q32 (which includes CFH and CFHR1-5) with AMD [9–13, 17, 19–21].