RAF1 and malignant peripheral nerve sheath tumor: Recently, hyperactivity in the HIPPO pathway was found to result in constitutively active YAP/TAZ oncoproteins in both sporadic and NF1-associated MPNST.96 This leads to stem cell-like characteristics, including resistance to chemotherapy.97 Targeting the HIPPO/YAP/TAZ pathway in combination with PDGFR/RAF1 signaling decreased tumor growth in mouse models and human MPNST cell lines.