Selumetinib, an oral MEK inhibitor, was studied in a phase 2 trial in patients with R/R AML or older untreated AML patients; in this study, 7% of patients had NRAS mutations and 2% of patients had KRAS mutations, but there was no response in the NRAS patients, and the only KRAS patient had an unconfirmed minor response with improvement in platelets [194]. This evidence concerns the gene KRAS and acute myeloid leukemia.