C6 and Alzheimer disease: While there is no genetic linkage of this allele to AD, another risk allele, rs1061170, is common to both AD and AMD (Zhang et al., 2016), and molecular analyses of drusen (AMD) and senile plaques (AD) reveal the presence of common complement components, including C3, C5, C6-9, and factors B, H, and I (Sivak, 2013), implying the occurrence of a common inflammatory response in both diseases, which also shares similarities to complement activation during BM (Molins et al., 2018).