In a study by Philip C. De Witt Hamer et al., the effect of six small molecule kinase inhibitors towards PDGFR; EGFR; mTOR; kinase insert domain receptor (KDR); fms-related tyrosine kinase 1 (FLT1) and protein kinase C beta (PKCb) were analyzed in clinical studies with GBM patients [19]. This evidence concerns the gene MTOR and glioblastoma.