Anti-L21mt antibodies enable researchers to detect and measure the L21mt antigen in biological samples. This target is a reported synonym of the MRPL21 gene, which encodes mitochondrial ribosomal protein L21. This protein is known to function in mitochondrial translation, among other biological roles. The human version of L21mt has a canonical amino acid length of 205 residues and a protein mass of 22.8 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the mitochondria of cells and widely expressed in many tissue types. L21mt is a member of the Bacterial ribosomal protein bL21 protein family.