[Isoform 1]: UDP-glucuronosyltransferase (UGT) that catalyzes phase II biotransformation reactions in which lipophilic substrates are conjugated with glucuronic acid to increase the metabolite's water solubility, thereby facilitating excretion into either the urine or bile (PubMed:11300766). Essential for the elimination and detoxification of drugs, xenobiotics and endogenous compounds (PubMed:11300766). Catalyzes the glucuronidation of endogenous steroid hormones such as androgens (androsterone, 3alpha-androstanediol) and estrogens (estradiol, estrone) (PubMed:11300766). Catalyzes the glucuronidation of bile acid substrates, which are natural detergents for dietary lipids absorption (PubMed:11300766). Displays glucuronidation activity toward the phenolic compounds eugenol (PubMed:11300766). . [Isoform 2]: Lack UDP-glucuronosyltransferase (UGT) activity. . This is the function of Ensembl gene identifier ENSG00000135226 (UGT2B28, UDP glucuronosyltransferase family 2 member B28).