Anti-preproenkephalin antibodies enable researchers to detect and measure the preproenkephalin antigen in biological samples. This target is a reported synonym of the PENK gene, which encodes proenkephalin. This protein is known to function in pathways of aging and the response to oxidative stress, among other biological roles. The human version of preproenkephalin has a canonical amino acid length of 267 residues and a protein mass of 30.8 kilodaltons. It is reported to be localized in the cytoplasmic vesicles and is secreted of cells and notably expressed in the testis, caudate, and adrenal gland. Other names for this target antigen include PE, PENK-A, and proenkephalin-A. A number of preproenkephalin antibodies have been mentioned in research publications and have associated citations. Immunofluorescence is a widely used application for these antibodies. In addition, Immunohistochemistry is also a common application.