MAP2K1 and neurofibromatosis type 1: Selumetinib is an oral selective MEK1/2 inhibitor that is approved in the United States (US), the European Union (EU), and other countries for the treatment of pediatric patients (aged ≥2 years in the US and ≥3 years in the EU) with NF1 who have symptomatic, inoperable plexiform neurofibromas [10].