Treatment of these tumour lines with nanomolar concentrations of entrectinib (RXDX 101), an investigational Trk inhibitor29, 30, resulted in reduced cell viability and inhibition of Akt and Erk phosphorylation in Bcan-Ntrk1-positive glioma lines, but not in a control glioma line generated by ectopically expressing PDGFb (Fig. 4a,b)31. This evidence concerns the gene PDGFB and central nervous system cancer.