The conditioning intensity was defined as MAC when the total body irradiation (TBI) was administered for 4 days or longer, or when busulfan was administered for 3 days or longer. In contrast, the cases in which TBI was administered for less than 4 days or busulfan for less than 3 days were classified as reduced-intensity conditioning (RIC). Rabbit anti-thymocyte globulin (ATG; Sanofi-Aventis, Cambridge, MA) was administered to patients at various dosages to prevent GVHD. ATG was given in equally divided doses for 2 or 3 days from day − 3. All patients received calcineurin inhibitors, including cyclosporine or tacrolimus, with or without short-term methotrexate as immunosuppressants to prevent GVHD. Prophylaxis against infections included low-dose acyclovir, trimethoprim−sulfamethoxazole, antifungal agents (such as fluconazole), antibiotics (such as levofloxacin), and preemptive therapy with ganciclovir for patients with cytomegalovirus infection (on the basis of antigen or DNA testing). Half of the patients received ursodiol as prophylaxis against cholestasis.