The relevant frequency and prognostic impact of TP53 variants represented in <20% leukemic cells was recently reported by Rossi, et al.13 Of note, we show here that the majority of TP53 mutations, at baseline in our inactive CLL subset, were under the sensitivity of conventional sequencing, and that they kept its independent impact on prognosis even when adjusting by high-throughput detected ATM, NOTCH1 and SF3B1 variants. The gene discussed is NOTCH1; the disease is B-cell chronic lymphocytic leukemia.