Sirolimus & Mycophenolate Mofetil as GVHD Prophylaxis in Myeloablative, Matched Related Donor HCT

Inclusion Criteria: * Disease Categories: (one of the following) * AML, age 2 - 60 years beyond 2nd remission or relapsed/refractory disease * AML, age 51-60 years of age, in first or subsequent remission or relapsed/refractory disease * AML with multilineage dysplasia * ALL, age 2 - 60 years beyond 2nd remission or relapsed/refractory disease * ALL, age 51 - 60 years in first or subsequent remission or relapsed/refractory disease * CML Beyond 2nd chronic phase or in blast crisis * MDS; Includes World Health Organization classifications of refractory anemia with excess blasts-1 (RAEB-1), RAEB-2 and therapy-related MDS * Myeloproliferative disorders; MDS with poor long-term survival including myeloid metaplasia and myelofibrosis * High risk NHL in first remission * Relapsed or refractory NHL * HL beyond first remission * Males and females of any ethnic background 2 - 60 years of age * Karnofsky Performance Status ≥ 70% or Lansky performance status \> 70% for patients \< 16 years of age. * Matched related donor identified: 6/6 HLA-A, B and DRB1 * Willingness to take oral medications during the transplantation period * Ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: * Prior myeloablative allogeneic or autologous HCT * HIV infection * Pregnant * Lactating females * Evidence of uncontrolled active infection * Organ Dysfunction: * Serum creatinine \> 1.5 mg/dL or 24 hour creatinine clearance \< 50 ml/min * Direct bilirubin, ALT or AST \> 2 x ULN * In adults DLCO \< 60% predicted and in children room air oxygen saturation \< 92% * In adults, left ventricular ejection fraction \< 45% and in children, shortening fraction \< 26% * Fasting Cholesterol \> 300 mg/dL or Triglycerides \> 300 mg/dL while on lipid-lowering agents. * Patients receiving investigational drugs unless cleared by the PI. * Patients with prior malignancies except basal cell carcinoma or treated carcinoma in-situ. * Cancer treated with curative intent \> 5 years will be allowed. * Cancer treated with curative intent ≤ 5 years will not be allowed with PI approval.