An open-label, non-randomized phase 2 clinical trial is undergoing to evaluate the efficacy of cobimetinib, a selective a reversible ATP-noncompetitive MEK inhibitor, in CMML patients with activated RAS pathway (mutations in NRAS, KRAS, PTPN11, FLT3,CBL, JAK2, BRAF, and NF1 at VAF ≥ 5%) (NCT04409639) [49]. This evidence concerns the gene NRAS and chronic myelomonocytic leukemia.