Anti-Gdown1 antibodies enable researchers to detect and measure the Gdown1 antigen in biological samples. This target is a reported synonym of the POLR2M gene, which encodes RNA polymerase II subunit M. This protein is known to function in intracellular signal transduction, among other biological roles. The human version of Gdown1 has a canonical amino acid length of 368 residues and a protein mass of 41.7 kilodaltons, although 6 isoforms have been identified. It is reported to be localized in the nucleus of cells. Gdown1 is a member of the GRINL1 protein family.