Anti-MRSR antibodies enable researchers to detect and measure the MRSR antigen in biological samples. This target is a reported synonym of the SMS gene, which encodes spermine synthase. This protein is known to function in metabolic processes, among other biological roles. The human version of MRSR has a canonical amino acid length of 366 residues and a protein mass of 41.3 kilodaltons, although 2 isoforms have been identified. It is reported to be notably expressed in many tissues, such as the ovary and testis. MRSR is a member of the Spermidine/spermine synthase protein family.