Of 37 loci that are BCL2 transgene specific, and 19 loci that are B cell specific, we find selected regions near known B cell lymphoma and leukemia drivers, including Pou2f2, Ebf1, Ikzf3, and Bcl6. The most specific locus for both BCL2 transgenic animals and for B cell lymphoma is Pou2f2 (Supplementary Fig. 11g) which is recurrently mutated in human FL and DLBCL. The gene discussed is IKZF3; the disease is leukemia.