Anti-SPG21 abhydrolase domain containing, maspardin antibodies are used for the immunodetection of the protein encoded by the SPG21 gene. In humans, the canonical protein has a reported length of 308 amino acid residues and a mass of 35 kDa. Its subcellular localization is in the membrane, Golgi, and cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. It is reported to be expressed in all tissues tested, including heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. A member of the AB hydrolase protein superfamily, it is believed to play a role as a negative regulatory factor in CD4-dependent T-cell activation. The gene encoding this protein is implicated in Spastic paraplegia. Other names for this target antigen include ACP33, BM-019, GL010, MAST, maspardin, SPG21, maspardin, acid cluster protein 33, and ABHD21. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.