BCL2 and lymphoma: FISH cytogenetics has revealed translocations involving the MYC locus which are sometimes accompanied by recurrent breaks at other loci, particularly the BCL2 gene on chromosome 18 or the BCL6 gene on chromosome 3. MYC+/BCL2+ cases account for 62% of double hit lymphomas, whereas MYC+/BCL6+ cases are much more rare at 8%.