PDGFRB and glioblastoma: Thus, Bielen et al., using pediatric glioblastoma (pGBM) cell lines, showed that the specific IGF-1R small molecule inhibitor NVPAEW541 or receptor silencing by siRNA decreased cell viability and induced G1 arrest in the cells, and that co-treatment of the cells with the PDGFR inhibitor imatinib and NVP-AEW541 resulted in a highly synergistic interaction in vitro.