The carbohydrates of glycoconjugates are highly diverse structures with variation in monosaccharide composition, glycosidic linkage positions, and branching of chains. Further diversity is added by the covalent addition of sulfate moieties to particular hydroxyl groups and amino groups of saccharides. The sulfate modifications of glycoproteins can be extensive in amount and frequently occur at high density. They can have a profound effect on the physiochemical properties of the glycoconjugates, at least in part through the addition of negative charge. Carbohydrate sulfation plays a critical role in many biologic processes. CHST5 belongs to the GST family of sulfotransferases, which also includes CHST1 (MIM 603797), CHST2 (MIM 603798), CHST3 (MIM 603799), and LSST. These enzymes are 6-O-sulfotransferases, which add sulfate to C6 of galactose (Gal), N-acetylgalactosamine (GalNAc), or N-acetylglucosamine (GlcNAc) (Lee et al., 1999 [PubMed 10491328]).