Anti-methyltransferase 21A, HSPA lysine antibodies are used for the immunodetection of the protein encoded by the METTL21A gene. In humans, the canonical protein has a reported length of 218 amino acid residues and a mass of 24.6 kDa. Its subcellular localization is in the cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. A member of the METTL21 protein family, it is reported to be a protein-lysine methyltransferase that selectively trimethylates residues in heat shock protein 70 (HSP70) family members. Other names for this target antigen include HSPA lysine methyltransferase, family with sequence similarity 119, member A, heat shock protein 70kDa lysine (K) methyltransferase, and protein N-lysine methyltransferase METTL21A. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.