To determine if Myc over-expression in human CB B cells cooperates with ΔEBNA2 EBV infection to form B-cell lymphomas in NSG mice in vivo, and/or alters the phenotype of ΔEBNA2 EBV-infected lymphomas, ΔEBNA2 EBV-infected CB B cells were co-infected with a Myc-expressing retrovirus as described in the Methods. The gene discussed is MYC; the disease is lymphoma.