Indeed, the mean percentage of CD34+/CD38−/NOTCH1-ICN+ and CD34+/CD38+/NOTCH1-ICN+ populations in NOTCH1 WT and mutated CLL was significantly higher than HDs samples (73.4 ± 22.9 and 83 ± 16.4 vs 33.3 ± 14.8%; 94.4 ± 7.3 and 92.8 ± 4.3 vs 47.9 ± 13.8%, respectively). This evidence concerns the gene CD34 and B-cell chronic lymphocytic leukemia.