Sorafenib, which targets VEGF, PDGFR, Raf kinase, receptor tyrosine kinase (KIT), and FMS-like tyrosine kinase 3 (FLT3), is approved for treating advanced hepatocellular carcinoma and advanced renal cell carcinoma.166 Neither primary glioblastoma nor recurrent glioblastoma patients had improved clinical outcomes when treated with sorafenib and TMZ in phase II clinical trials.167,168 Sorafenib has also been trialled as a combination therapy with temsirolimus, an mTOR inhibitor, in recurrent glioblastoma patients who had been previously treated with bevacizumab. Here, FLT3 is linked to hereditary clear cell renal cell carcinoma.