Algorithm for evaluation and treatment of chronic active EBV. allo, allogeneic; CNS, central nervous system; DA-EPOCH, dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin; GCV, ganciclovir; SAHA, suberoylanilide hydroxamic acid; SMILE, dexamethasone, methotrexate, ifosfamide, l-asparaginase, and etoposide.