Inclusion Criteria:

- Age 6 months - <18 years

- Measurable tumor by routine imaging or bone marrow biopsy

- Patient must have an 3/6, 4/6, or 5/6 human leukocyte antigen (HLA)-mismatched
related donor who is Epstein-Barr virus (EBV) seropositive

- Karnofsky score 60% or greater if 10yrs old or older, Lansky score 60% or greater if
under 10yrs old

- Pulse ox >90% on room air

- Recovered from toxic effects of prior chemotherapy

- Patient must not be pregnant

- Patient must be HIV negative

- Patient or responsible person must be able to understand and sign an informed consent

- Available donor without contraindication for stem cell collection

Exclusion Criteria:

- Pregnant and lactating women.

- Human immunodeficiency virus (HIV) positive patient.

- Uncontrolled intercurrent infection.

- Renal failure (Creatine > 1.5 or Creatinine Clearance < 40 ml/min/1.73m2)

- Active hepatitis or cirrhosis with liver test values greater than 3 times normal

- NOTE: Patients who would be excluded from the protocol strictly for laboratory
abnormalities can be included at the investigator's discretion, after review by the
Children's Mercy Hospital ethics board

- Donor Inclusion/Exclusion Criteria

- Donor must be in good health based on review of systems and results of physical
examination, and routine testing per standards of good medical care.

- Female donors of childbearing age must have a negative pregnancy test and must not be
lactating

- EBv seropositive

- Donor stem cells should be human leukocyte antigen (HLA) typed using molecular
methods. See section 6.1.3 for HLA matching requirements.