Although the recommended cut off to report TP53 mutation in CLL was previously defined to 10% and would have led to the clinical management of 32 patients, lowering this value to either 5 or 1% allowed the detection of 4 and 16 TP53 mutated patients respectively confirming the presence of a significant number of patients with only low burden variants (Supplementary Fig. S6A). The gene discussed is TP53; the disease is B-cell chronic lymphocytic leukemia.