Background Plexiform neurofibromas (PN) are the most frequent tumors associated with Neurofibromatosis type 1 (NF-1). PN can cause significant complications, including pain, functional impairment, and disfigurement. There is no efficient medical treatment and, surgical resection of large PN is frequently infeasible. Selumetinib (AZD6244/ARRY-142886) is a mitogen-activated protein kinase enzyme (MEK1/2) inhibito...