Consequently, 6 out of 20 CLL cases studied in detail here (30%) possess the ancient/recent NOTCH2 haplotype combination *1A01/*1a4 which is consistently associated with the recurrent NOTCH2∆NRR-DEL2 mRNA deletion in CLL cells (Table 1). Here, NOTCH2 is linked to B-cell chronic lymphocytic leukemia.