HTRA, or HtrA serine peptidase 1, is a human gene encoded by HTRA1. It may also be known as: Serine protease HTRA1; High-temperature requirement A serine peptidase 1; L56; Serine protease 11; Serine protease HTRA1 ; ARMD7; CARASIL; HtrA; ORF480; PRSS11. The encoded protein is an enzyme with an amino acid length of 480 and a mass of 51.3 kDa. HTRA is a member of the Peptidase S1C family. Homologs of this gene exist in other organisms, including: Mouse, Frog.