Whilst the association of Epstein-Barr virus (EBV) with Burkitt lymphoma (BL) has long been recognized, the precise role of the virus in BL pathogenesis is not fully resolved. EBV can be lost spontaneously from some BL cell lines, and these EBV-loss lymphoma cells reportedly have a survival disadvantage. We have generated an extensive panel of EBV-loss clones from multiple BL backgrounds and examined their phenotype comparing them to their isogenic EBV-positive counterparts. Whilst loss of EBV from BL cells is rare, it is consistently associated with an enhanced predisposition to undergo apoptosis and reduced tumorigenicity in vivo. We investigated whether there were common gene expression changes between EBV-positive and loss clones derived for four endemic Burkitt lyphoma cell lines that could explain the apoptosis sensitivity of clones that had lost EBV.