MTOR and malignant peripheral nerve sheath tumor: Furthermore, a multicenter phase I of pexidartinib, a CSF-1 receptor inhibitor targeting the polarization of tumor-associated macrophages in MPNST, combined with sirolimus, an mTOR inhibitor, showed safety and overall clinical benefit in 12 of 18 subjects [130,131], and a subsequent phase II study is currently underway (NCT02584647).