The function of PIGN (phosphatidylinositol glycan anchor biosynthesis class N, Ensembl gene identifier ENSG00000197563) is as follows. Ethanolamine phosphate transferase that catalyzes an ethanolamine phosphate (EtNP) transfer from phosphatidylethanolamine (PE) to the 2-OH position of the first alpha-1,4-linked mannose of a 2- acyl-6-[alpha-D-mannosyl-(1->6)-alpha-D-mannosyl-(1->4)-alpha-D- glucosaminyl]-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol (also termed H3) intermediate to generate a 2-acyl-6-[alpha-D-mannosyl- (1->6)-2-phosphoethanolamine-alpha-D-mannosyl-(1->4)-alpha-D- glucosaminyl]-1-(1-radyl,2-acyl-sn-glycero-3-phospho)-1D-myo-inositol and participates in the eighth step of the glycosylphosphatidylinositol-anchor biosynthesis (By similarity). Also transfers the EtNP on a mannosyl GPI intermediate, 2-acyl-6-(alpha-D- mannosyl-(1->4)-alpha-D-glucosaminyl)-1-(1-radyl,2-acyl-sn-glycero-3- phospho)-1D-myo-inositol (also termed H2) (By similarity). May act as suppressor of replication stress and chromosome missegregation (PubMed:23446422). {ECO:0000250|UniProtKB:Q9R1S3, ECO:0000269|PubMed:23446422}.