Moreover, about 30% of CLL patients share nearly identical VDJ rearrangements of the BCR Ig, forming stereotyped subsets, with subset 8 (IGHV4-39/IGHD6-13/IGHJ5) frequently linked to aggressive disease, trisomy 12, and NOTCH1 mutations [78,79]. This evidence concerns the gene NOTCH1 and B-cell chronic lymphocytic leukemia.