Phase II enzymes mature at different rates, which can vary significantly among individuals. For instance, glucuronidation, mediated by the UDP-glucuronosyltransferases (UGTs), is relatively immature in neonates but reaches adult levels by the age of 3-4 years. Sulfation, catalyzed by sulfotransferases (SULTs), is well-developed at birth, allowing neonates to conjugate certain compounds efficiently.