Anti-LIM Domain Only 4 antibodies are used in the immunodetection of the protein encoded by the LMO4 gene. In humans, the canonical protein has a reported length of 165 amino acid residues and a mass of 18 kDa. The LIM domain only 4 protein is involved with the regulation of transcription, among other functions. Other names for this target antigen include LIM domain only protein 4, LIM-only 4 protein, breast tumor autoantigen, and LIM domain transcription factor LMO4.