Inclusion Criteria:

- Patient age < 22 years.

- Both genders and all races are eligible.

- Undergoing a T-cell depleted allogeneic HPCT from a related HLA partially matched
(two antigen mismatched, or haplodisparate) donor or a mismatched unrelated donor

- Must be willing to sign a written informed consent.

- Patient Organ Status at the time of enrollment (pre-transplant)

- Lansky or Karnofsky score > 50

- Echocardiogram shortening fraction > 27%

- Renal function: serum creatinine < 2 x normal for age

- DLCO > 50% predicted in patients old enough to comply with PFTs or no baseline
oxygen requirement for younger patients.

- Hepatic: AST, ALT < 5x upper limit of normal; bilirubin < 2.0 mg/dl

- Sexually active patients must be willing to utilize one of the more effective birth
control methods for 6 months following CTL infusion. The male partner should use a
condom.

- Patients must be between 28 and 60 days post T-cell depleted allogeneic HPCT

- Patients must meet the following criteria (within 72 hours of CTL infusion):

- Achieved primary engraftment with an ANC of at least 1000 per μl for 3
consecutive days.

- No oxygen requirement with oxygen saturations > 90%.

- AST, ALT < 5x upper limit of normal for age; bilirubin < 2 mg/dl.

- Hemoglobin > 8 gm/dl prior to infusion. (May be transfusion dependent).

- Renal function: serum creatinine < 2 x normal for age.

- The Patient must not have the following conditions on the day of CTL infusion:

- Exhibit overt hematologic manifestations of relapse or persistent disease.

- Evidence of recurrent/persistent disease based primarily on flow cytometry,
cytogenetics, chimerism analysis, or other molecular studies does not by itself
represent grounds for exclusion.

Exclusion Criteria:

- Currently enrolled on another Phase I clinical trial.

- Pregnant or nursing

- Overt hematologic manifestations of relapse or persistent disease

- Having > grade 1 graft-versus-host disease.