IGF1R and central nervous system cancer: Satoro et al. recently demonstrated up-regulation of the IGF1R signaling in glioma stem cells following repeated radiation therapy (RTx), inducing adaptive radioprotection and escape from RTx-induced cytotoxicity.47,48 Further, the combination treatment of radio-resistant glioma stem cells with RTx and IGF1R inhibition resulted in a robust increase in radiosensitivity, suggesting that the specific inhibition of IGF1R signaling is a promising strategy to reverse RTx resistance and improve patient survival.