The efficacy of MEK inhibitors on myeloid NRAS/KRAS mutated leukemic cells have been tested using two different mouse models: a Mx1-Cre, KrasLSL-G12D mice, which develop a fatal myeloproliferative neoplasm [88] and mice transplanted with NRAS mutated AML cells (NrasG12D AML cells) [89]. Here, NRAS is linked to myeloproliferative disorder.