In fact, one clinical trial reported increased drug exposure and dose-limiting toxicities specifically in NF1 children compared to patients with other advanced cancers, although this outcome has not been reported with MEK inhibitors.39 To the best of our knowledge, selumetinib entry and distribution in CNS tissue has not been evaluated in other preclinical models of NF1 and compared to WT. Here, MAP2K7 is linked to neurofibromatosis type 1.