Anti-FKSG33 antibodies enable researchers to detect and measure the FKSG33 antigen in biological samples. This target is a reported synonym of the RNF32 gene, which encodes ring finger protein 32. This protein is believed to play a role in sperm formation. The human version of FKSG33 has a canonical amino acid length of 362 residues and a protein mass of 41.5 kilodaltons, although 5 isoforms have been identified. It is reported to be localized in the cytoplasm of cells and notably expressed in the testis.