HTRA1-IN-1 (Compound 17) is a selective inhibitor for serine protease high temperature requirement A serine peptidase 1 (HTRA1), with IC50 of 13 nM. HTRA1-IN-1 is potential for ameliorating HTRA1-related diseases, such as age-related macular degeneration (AMD), osteoarthritis, and rheumatoid arthritis[1].