Anti-serine and arginine-rich splicing factor 4 antibodies are protein reagents that detect specific antigens. The serine and arginine-rich splicing factor 4 antigen is another term for the human protein serine and arginine rich splicing factor 4, encoded by the SRSF4 gene. The protein is reported to play a role in alternative splice site selection during pre-mRNA splicing. Canonically, it has an amino acid length of 494 residues and a mass of 56.7 kilodaltons. Its subcellular localization is in the nucleus and it is widely expressed in many tissue types. The serine and arginine-rich splicing factor 4 protein is a member of the Splicing factor SR protein family.