NRAS and cutaneous mastocytosis: More recently, the increasing understanding of CM biology has resulted in the development of other therapeutic strategies, including the use of selective inhibitors of the mitogen-activated protein kinase (MAPK) signaling pathway, which is frequently dysregulated in CM patients due to activating mutations in the proto-oncogenes BRAF or NRAS, with a frequency of 50–70% and 15–30%, respectively.