Anti-HTRA4 antibodies are used in the immunodetection of the protein HtrA serine peptidase 4. In humans, the canonical protein has a reported length of 476 amino acid residues and a mass of 51 kDa. It has been described to be a secreted protein. It is notably expressed in the placenta. A member of the Peptidase S1C protein family, HTRA4 is known to be involved with the regulation of apoptosis and proteolysis. Synonyms for this target antigen include high-temperature requirement factor A4, probable serine protease HTRA4, and serine protease HTRA4. HTRA4 gene orthologs have been reported in the mouse, rat, bovine and chimpanzee species. Western Blot is the most common application for the HTRA4 antibodies listed below. Immunofluorescence and Immunohistochemistry are also common applications.