Circumstantial evidence for a protective role of autoreactive CD4+ T cells has already been obtained in preclinical lymphoma models and lymphoma patients: CD4+ T cells that recognize non-viral antigens can prevent B cell lymphomas in mice transgenic for the EBV latent membrane protein LMP1 [45], and five of six patients with Hodgkin's-like and Burkitt's-like post-transplant lymphoproliferative disease responded to treatment with allogeneic T-cell preparations, although in some cases the tumor cells did not express the viral antigens recognized by the infused T cells [11]. Here, CD4 is linked to B-cell non-Hodgkin lymphoma.