The BCL2 negativity by IHC using two BCL2 antibodies was confirmed by the absence of IGH::BCL2 rearrangement by FISH. BCL6 rearrangements and 1p36 deletions were also negative by FISH. Next-generation gene sequencing was performed for additional endorsement of the morphologic diagnosis of CD23+ dFL and CLL/SLL due to the distinct molecular profiles of each entity. This evidence concerns the gene BCL2 and B-cell chronic lymphocytic leukemia.