For example, the same study by Hecker et al. looked at the plasma levels of AMD patients carrying a protective haplotype in the C2/CFB locus (rs4151667), which has been found to be associated with reduced levels of the complement activator Ba, whereas another protective haplotype in the CFB locus (rs641153) was found to be associated with decreased levels of another complement activator (C3a) [53]. This evidence concerns the gene C3 and age-related macular degeneration.