Anti-AFF1 antibodies are used in the immunodetection of the protein ALF transcription elongation factor 1. In humans, the canonical protein has a reported length of 1210 amino acid residues and a mass of 131.4 kDa. Its subcellular localization is in the nucleus. Up to 3 different isoforms have been reported for this protein. A member of the AF4 protein family, AFF1 is known to be involved with the regulation of gene expression. Synonyms for this target antigen include FEL, MLLT2, PBM1, AF4/FMR2 family member 1, ALL1-fused gene from chromosome 4 protein, and AF4. AFF1 gene orthologs have been reported in the mouse, rat, bovine, frog, chimpanzee and chicken species. A number of AFF1 antibodies have been mentioned in research publications and have associated citations. Immunohistochemistry is a widely used application for these antibodies. Western Blot and Immunofluorescence are also common applications.