MTOR and cancer: Based on the findings in correlation with cell apoptosis and our experiments in NPC cell lines that have showed that CAPRIN1 protein was down-regulated in the treatment of cisplatin (Fig. 1A), we speculated that CAPRIN1 might have effects on the drug response to mTOR inhibitors, which a promising anti-cancer agent targeting mTOR signaling that has shown efficacy in NPC in one of our previous studies [19].