Anti-FOXP4 antibodies are used in the immunodetection of the protein forkhead box P4. In humans, the canonical protein has a reported length of 680 amino acid residues and a mass of 73.5 kDa. Its subcellular localization is in the nucleus. Alternative splicing is reported to yield 3 different isoforms for this protein. FOXP4 is reported to be a transcriptional repressor that represses lung-specific expression. Synonyms for this target antigen include fork head-related protein like A, winged-helix repressor FOXP4, and forkhead box protein P4.