NPM1 and acute myeloid leukemia: Moreover, in comparison with AML showing NPM1 mutations, NPM1-mutated MNs exhibited significantly fewer mutations in IDH1, IDH2 and FLT3 genes, and a trend toward fewer gene mutations involving NRAS and KRAS. Most patients with NPM1-mutated MNs (73%) received upfront treatment with hypomethylating agents (HMA) and thirteen of them (39%) progressed to AML at a median time of 5.2 months, while none of the cases receiving intensive induction chemotherapy experienced leukemic evolution.