HTRA1 and age-related macular degeneration: Analysis of the Regulators of Complement Activation (RCA) alpha block located on chromosome 1q32 that contain the CFH, CFH related 1–5 and F13B genes and analysis of the chromosome 10q26 region containing the ARMS2 and HTRA1 genes has identified a series of single nucleotide polymorphisms (SNPs) associated with both risk of, and protection against, AMD [10], [11].