HTRA1 and age-related macular degeneration: One of the earliest discovered and most significant of the susceptibility loci associated with AMD is the region of chromosome 10q26 spanning the age-related maculopathy susceptibility 2 (ARMS2) gene coding region and the high-temperature requirement factor A serine peptidase 1 (HTRA1) gene promoter [44,289,290,291,292,293,294].