The protein encoded by PIGY (phosphatidylinositol glycan anchor biosynthesis class Y)is part of the GPI-N-acetylglucosaminyltransferase (GIP-GnT) complex which initiates the biosynthesis of glycosylphosphatidylinositol (GPI). GPI is synthesized in the endoplasmic reticulum and serves as an anchor for many surface proteins. Proteins containing GPI anchors can have an important role in cell-cell interactions. The transcript for PIGY is bicistronic. The downstream open reading frame encodes this GPI-GnT complex protein, while the upstream open reading frame encodes a protein with unknown function, as represented by GeneID: 100996939.