BCL2 and lymphoma: The excess lymphocytes they accumulated had failed to die in response to physiological cues and resisted diverse cytotoxic agents, including chemotherapeutic drugs.13, 14, 15, 16 Notably, mice co-expressing BCL-2 and myc transgenes developed lymphomas markedly faster than littermates expressing either transgene alone,17 validating BCL-2 as an oncogene.