Anti-Glycogenin 1 antibodies are used in the immunodetection of the protein encoded by the GYG1 gene. In humans, the canonical protein has a reported length of 350 amino acid residues and a mass of 39.4 kDa. Alternative splicing is reported to yield 3 different isoforms for this protein. It is reported to be highly expressed in skeletal muscle and heart, with lower levels in the brain, lung, kidney and pancreas. The glycogenin 1 protein is a member of the Glycosyltransferase 8 protein family. Post-translational modifications have been described, including glycosylation and phosphorylation. Other names for this target antigen include GYG, GN-1, glycogenin glucosyltransferase, and GSD15.