More importantly, activating PTPN11 mutations have been described in KMT2A-rearranged ALL31,33 and AML34,36,40 with a frequency of ca.3% for AML and 4% to 13% in ALL (Fig. 2 and Supplemental Table 1, Supplemental Digital Content). This evidence concerns the gene PTPN11 and acute lymphoblastic leukemia.