Researchers have revealed that the pathogenesis of some entities is characterized by distinct chromosomal aberrations, somatic mutations, or gene expression signatures, for instance, IGH-BCL2 in FL, IGH-CCND1 in MCL, +12 in CLL/SLL, BIRC3-MALT1 fusion in MALTL, MYD88 L265P in LPL/WM, BRAF V600E in HCL, and SOX11 overexpression in conventional MCL (cMCL)2–7. This evidence concerns the gene BCL2 and B-cell chronic lymphocytic leukemia.