The function of ENSG00000138653 (NDST4, N-deacetylase and N-sulfotransferase 4) is as follows. Essential enzyme that catalyzes the N-sulfation of glucosamine (GlcNAc) of the glycosaminoglycan in heparan sulfate (PubMed:29158133). Modifies the GlcNAc-GlcA disaccharide repeating sugar backbone to make N-sulfated heparosan, a prerequisite substrate for later modifications in heparin biosynthesis (PubMed:29158133). Has no deacetylase activity but high sulfotransferase activity (PubMed:29158133). Plays a crucial role in the differentiation of colonic progenitor cells (By similarity). .