Anti-PS1 antibodies enable researchers to detect and measure the PS1 antigen in biological samples. This target is a reported synonym of the PSEN1 gene, which encodes presenilin 1. This protein is known to function in the apoptotic pathway and blood vessel development, among other biological roles. The human version of PS1 has a canonical amino acid length of 467 residues and a protein mass of 52.7 kilodaltons, although 7 isoforms have been identified. It is reported to be widely expressed in many tissue types. PS1 is a member of the Peptidase A22A protein family.