EPHA4 and lymphoproliferative syndrome: Interestingly, EBV LMP1 is a known regulator of EphA4 expression, and an inverse correlation of EBV infection and EphA4 expression was observed in EBV+ and EBV− diffuse large B-cell lymphoma (DLBCL) and EBV− tonsils compared to EBV+ posttransplant lymphoproliferative disorder.