PDGFRB and central nervous system cancer: Imatinib mesylate is a multitargeted tyrosine kinase KIT, Bcr-Abl and PDGFR inhibitor; this drug was evaluated in recurrent glioma patients (including GBM) in two phase II trials, alone or in combination with hydroxyurea: single agent and combination treatment were well tolerated despite limited antitumor activity [93].