Ethanolamine phosphate transferase involved in glycosylphosphatidylinositol-anchor biosynthesis. Transfers ethanolamine phosphate to the GPI second mannose. Glycolipid biosynthesis; glycosylphosphatidylinositol-anchor biosynthesis. Forms a complex with PIGF. PIGF is required to stabilize it. Competes with PIGO for the binding of PIGF. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the PIGG/PIGN/PIGO family. PIGG subfamily. Truncated C-terminus. Truncated N-terminus. Truncated N-terminus.