Anti-Sun4 antibodies enable researchers to detect and measure the Sun4 antigen in biological samples. This target is a reported synonym of the SPAG4 gene, which encodes sperm associated antigen 4. This protein is known to function in cell differentiation and spermatogenesis, among other biological roles. The human version of Sun4 has a canonical amino acid length of 437 residues and a protein mass of 48.2 kilodaltons. It is reported to be localized in the membrane, nucleus, and cytoplasm of cells and notably expressed in the testis. Other names for this target antigen include CT127 and sperm-associated antigen 4 protein. Indicated applications for Sun4 antibodies listed below include ELISA, Western Blot, and Immunohistochemistry.