More than a third of AYAs with MPNST had an NF-1 mutation, which is associated with worse prognosis compared with sporadic MPNST.10,24 Patients with MPNST respond relatively poorly to chemotherapy and those arising in the setting of NF-1 mutations may have inferior response rates.25,26 Loss of the NF-1 protein leads to activation of the RAS signaling pathway; however, therapeutic attempts to target RAS signaling and downstream pathways have had disappointing results.27 Clinical trials evaluating multiagent strategies (such as MEK and mTOR inhibitors) are ongoing and results are awaited. The gene discussed is MTOR; the disease is malignant peripheral nerve sheath tumor.