It is important to note that, although the new WHO classification states that the presence of the NPM1 variant alone leads to a diagnosis of AML independently from the blast percentage [4], such a finding in the ICC does not automatically define de novo AML in the setting of known CMML, as a bone marrow blast count of at least 10% is also required [4]. This evidence concerns the gene NPM1 and acute myeloid leukemia.