UDP-Glucuronosyltransferases (UGTs) are glycoproteins, localized in endoplasmic reticulum (ER) and nuclear membranes, which catalyze the confugation of a broad variety of lipophilic aglycon substrates with glucuronic acid using UDP-glucuronic acid (UDP-GlcUA) as the sugar donor. The major function of glucuronidation is to change hydrophobic compounds into hydrophilic derivatives, a process which facilitates their detoxification and excretion. However, it is also widely recognized that glucuronidation can result in compounds which are biologically active or demonstrate increased toxicity. UGTs, like other drug-metabolizing enzymes, have been postulated to be involved in controlling the steady state concentrations of nuclear receptor ligands for interactions with nuclear receptors [1,2]. One of the isoforms from the UGT2B subfamily, UGT2B7, has been found to be a major human UGT2B isoform, involved in the glucuronidation of a variety of endogenous compounds and xenobiotics. In this review, we included all available information from our studies and those of other investigators on a) the history of the identification and expression of UGT2B7 in human tissues, b) the substrate specificity of UGT2B7, c) the extrahepatic localization of UGT2B7 d) the nuclear localization of UGT2B7 and e) characterization of the UGT2B7 gene and promoter.