This strategy clearly showed that the BPS-creating NOTCH2*1A01 variant rs2453058 (a) and the BPS-destroying NOTCH2*1a4 variant rs5025718 (b) are recombined by reciprocal crossing over in all six NOTCH2*1A01/*1a4 CLL cases leading to mutated rs5025718/rs2453058 (+/+) ba and (−/−) ab alleles (Figure 5a,b). The gene discussed is NOTCH2; the disease is B-cell chronic lymphocytic leukemia.