That said, at the individual gene level, NOTCH1 mutations exhibited a significantly lower prevalence in HC-MBL compared to CLL (3.2% versus 11.6%, respectively) (P=0.050) (38); moreover, SF3B1 mutations were even more scarce in HC-MBL (1.5%) versus CLL (~10%) (39). The gene discussed is NOTCH1; the disease is B-cell chronic lymphocytic leukemia.