Anti-serine and arginine-rich splicing factor 9 antibodies are used for the immunodetection of the protein encoded by the SRSF9 gene. In humans, the canonical protein has a reported length of 221 amino acid residues and a mass of 25.5 kDa. Its subcellular localization is in the nucleus. It is notably expressed at high levels in the heart, kidney, pancreas and placenta, and at lower levels in the brain, liver, lung and skeletal muscle. A member of the Splicing factor SR protein family, it is reported to play a role in constitutive splicing and can modulate the selection of alternative splice sites. Post-translational modifications have been described, including phosphorylation. Other names for this target antigen include SRp30c, serine/arginine-rich splicing factor 9, SR splicing factor 9, pre-mRNA-splicing factor SRp30C, splicing factor, arginine/serine-rich 9, and SFRS9. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish and chimpanzee species.