Anti-regulatory factor X2 antibodies are used in the immunodetection of the protein encoded by the RFX2 gene. In humans, the canonical protein has a reported length of 723 amino acid residues and a mass of 80 kDa. Its subcellular localization is in the nucleus and cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. A member of the RFX protein family, it is reported to be a transcription factor that acts as a key regulator of spermatogenesis. Other names for this target antigen include HLA class II regulatory factor RFX2, regulatory factor X, 2 (influences HLA class II expression), trans-acting regulatory factor 2, and DNA-binding protein RFX2.