GVHD PROPHYLAXIS: Patients receive cyclophosphamide IV over 2 hours on days 3 and 4, tacrolimus orally (PO) BID or IV continuously on days 5-180, mycophenolate mofetil PO three times daily (TID) on days 5-35 and filgrastim subcutaneously (SC) beginning day 5 until absolute neutrophil count (ANC) >= 1,000/mm^3 for 3 consecutive days.