Genetic alterations in the CLL cluster in the characteristic pathways included BCR and toll-like receptor (TLR) signalling (BTK, IGHV, PLCγ2, EGR2, BCOR, MYD88, TLR2, IKZF3), DNA damage response (ATM, TP53, POT1), NOTCH1 signalling (NOTCH1 and FBXW7), apoptosis (miR15/16 and BCL2), NF-κB signalling (BIRC3, NFKBIE, TRAF2, TRAF3), and RNA splicing and metabolism (SF3B1, U1, XPO1, DDX3X, and RPS15). This evidence concerns the gene NOTCH1 and B-cell chronic lymphocytic leukemia.