Anti-p74 antibodies enable researchers to detect and measure the p74 antigen in biological samples. This target is a reported synonym of the STRBP gene, which encodes spermatid perinuclear RNA binding protein. This protein is known to function in spermatid development, among other biological roles. The human version of p74 has a canonical amino acid length of 672 residues and a protein mass of 73.7 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the cytoplasm of cells and notably expressed in many tissues, such as the caudate, testis, and bronchus. Other names for this target antigen include HEL162, ILF3L, and SPNR.