HTRA1 and age-related macular degeneration: In recent years, human high temperature requirement A1 (HtrA1) has been the subject of drug discovery efforts in age-related macular degeneration (AMD) (Ciferri et al., 2015), owing to the prevalence of high-frequency HTRA1 variants in affected subjects (Dewan et al., 2006; Yang et al., 2006).