Anti-hemW antibodies enable researchers to detect and measure the hemW antigen in biological samples. This target is a reported synonym of the RSAD1 gene, which encodes radical S-adenosyl methionine domain containing 1. This protein is believed to be a heme chaperone, appears to bind heme. The human version of hemW has a canonical amino acid length of 442 residues and a protein mass of 48.7 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the mitochondria of cells and notably expressed in many tissues, such as the cerebellum and cerebral cortex. hemW is a member of the Anaerobic coproporphyrinogen-III oxidase protein family.