Anti-GAAP antibodies enable researchers to detect and measure the GAAP antigen in biological samples. This target is a reported synonym of the TMBIM4 gene, which encodes transmembrane BAX inhibitor motif containing 4. This protein is known to function in the apoptotic pathway, among other biological roles. The human version of GAAP has a canonical amino acid length of 238 residues and a protein mass of 27 kilodaltons. It is reported to be localized in the Golgi of cells. GAAP is a member of the BI1 protein family.