Cytotoxic T Lymphocytes in Treating Patients With Malignancies With BK and/or JC Virus

Inclusion Criteria: * Patients ≥ 2 years. English and non-English speaking patients are eligible. * Immunocompromised patients; and/or Non-immunocompromised patients with PML/JC virus Encephalitis; and/or patients with any type of malignancies; and/or HIV/AIDs; and/or history of solid organ transplant; and/or Merkel polyoma-virus related Merkel cell tumor(s) with measurable disease on imaging per RECIST criteria. * Patients with microscopic hematuria OR biopsy proven BK nephritis and urine or blood PCR positive for BK virus and/or JC viral encephalitis and/or JC end-organ disease and/or polyomavirus. * Clinical status at enrollment to allow tapering of steroids to less than 0.5 mg/kg/day of prednisone. * Patients who are currently receiving treatment with cidofovir, leflunomide, or other antiviral therapy with no response, will be eligible for CTL infusion. * Written informed consent and/or signed assent from patient, parent or guardian. Patients with cognitive impairments are eligible. * Negative pregnancy test in female patients of childbearing potential, defined as not post-menopausal for 12 months or no previous surgical sterilization. Women of child bearing potential must be willing to use an effective contraceptive measure while on study. * Patients enrolled on this study may be enrolled on other IND studies at the discretion of the PI. * Patients may be re-enrolled in the protocol should the infection re-occur, provided they meet all the other eligibility criteria at …