Anti-CAPRI antibodies enable researchers to detect and measure the CAPRI antigen in biological samples. This target is a reported synonym of the RASA4 gene, which encodes RAS p21 protein activator 4. This protein is known to function in intracellular signal transduction, among other biological roles. The human version of CAPRI has a canonical amino acid length of 803 residues and a protein mass of 90.5 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the cell membrane and cytoplasm of cells. Other names for this target antigen include GAPL and ras GTPase-activating protein 4.