MYC and Burkitt lymphoma: Although these models have helped to investigate the role MYC plays in oncogenesis overall, or to elucidate the cooperativity among diverse oncogenes (79–82), they are not considered informative for dissecting the pathogenesis of BL; moreover, the nearly full penetrance of immature B-cell lymphomas in some of these models may complicate the study of the GC B cell response, as mice frequently die before becoming immunologically mature.