Anti-tRNA-histidine guanylyltransferase antibodies enable researchers to detect and measure the tRNA-histidine guanylyltransferase antigen in biological samples. This target is a reported synonym of the THG1L gene, which encodes tRNA-histidine guanylyltransferase 1 like. This protein is known to function in the response to oxidative stress, among other biological roles. The human version of tRNA-histidine guanylyltransferase has a canonical amino acid length of 298 residues and a protein mass of 34.8 kilodaltons. It is reported to be localized in the mitochondria and cytoplasm of cells and widely expressed in many tissue types. tRNA-histidine guanylyltransferase is a member of the TRNA(His) guanylyltransferase protein family.