Although SF3B1 mutation was not detected in CD34+CD19− cells, suggesting it as a late event in B-CLL differentiation, one out of four SF3B1 mutated patients (ID-43) carried a mutation in a high percentage of the whole population of CD34+ progenitors, similar to results from a previous study [18]. The gene discussed is CD19; the disease is B-cell chronic lymphocytic leukemia.