Anti-AAR2 splicing factor antibodies are used for the immunodetection of the protein encoded by the AAR2 gene. In humans, the canonical protein has a reported length of 384 amino acid residues and a mass of 43.5 kDa. A member of the AAR2 protein family, it is a known component of the U5 snRNP complex that is required for spliceosome assembly and for pre-mRNA splicing. Other names for this target antigen include CGI-23, protein AAR2 homolog, AAR2 splicing factor homolog, and C20orf4. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.