BCL6 and B-cell chronic lymphocytic leukemia: Clinically, in addition to COO classification, DLBCL is also further stratified by the presence of BCL2 (B-cell CLL/lymphoma 2), BCL6 (B-cell CLL/lymphoma 6), and MYC (Myelocytomatosis) chromosomal translocations and/or expression, as determined by fluorescent in situ hybridization (FISH) or IHC, respectively.