Lymphoma relapse with loss of EBV positivity. (A) A patient who received LMP2-specific T cells as adjuvant therapy after undergoing allogeneic transplantation for an EBV⁺ HL, as demonstrated by positive LMP1 staining (×40), was noted to have progressive disease shortly after receiving LMP2-specific T cells. (B) However, biopsy of the relapsed lymphoma demonstrated that the tumor was no longer EBV⁺.