Anti-BCAA antibodies enable researchers to detect and measure the BCAA antigen in biological samples. This target is a reported synonym of the ARID4B gene, which encodes AT-rich interaction domain 4B. This protein is known to function in the regulation of cell migration and the regulation of transcription, among other biological roles. The human version of BCAA has a canonical amino acid length of 1312 residues and a protein mass of 147.8 kilodaltons, although 4 isoforms have been identified. It is reported to be localized in the nucleus and cytoplasm of cells and notably expressed in many tissues, such as the colon, tonsil, and cerebellum. This target antigen may also be known as BRCAA1.