Although the 13 genes that we identified were not on the list of genes identified using a forward genetic screen in Schwann cells utilizing the Sleeping Beauty (SB) transposon-based somatic mutagenesis system in mice to determine the driver genes of MPNST [41], PTPN11 missense mutation and NF1 homozygous loss were recently detected in clinical specimens of MPNSTs [42], suggesting that the combination of PTPN11 and NF1 mutations may give rise to the persistent activation of both RAS-ERK and PI3K-Akt-mTOR pathways and to malignant transformation. Here, NF1 is linked to malignant peripheral nerve sheath tumor.