PDGFA and glioblastoma: Although the data in vitro and in vivo support the potent inhibitory effects of targeting PDGFRA in GBM cells,26,27 clinical trials of single PDGFRA inhibitor have failed to show anti-tumor effects.28,29 Therefore, the regulation mechanisms on PDGFA and PDGFRA in GBM need be clarified before clinical application of strategies targeting PDGFA/PDGFRA signaling axis.