At steady state or after acute immunization with a T-cell dependent antigen, BCL2 alone was not able to drive progression of BCL2-expressing cells into a tumor after 18 months of follow-up, confirming that lymphomagenesis is a stepwise process where premalignant B cells require the accumulation of secondary (epi)genetic alterations to progress into a tumor. This evidence concerns the gene BCL2 and neoplasm.