MTOR and acute promyelocytic leukemia: ATRA is an active metabolite of vitamin A and used as an effective antitumor in acute promyelocytic leukemia,82 And emerges the antitumor effects in other tumors by a combination of ATRA with other agents, including chemotherapy, epigenetic modifiers, and others.83 ATRA also has been demonstrated that exert the antitumor effects on NPC.84 Temsirolimus is an mTOR inhibitor widely used in renal cell carcinoma and achieves good efficacy in the therapeutic course,85 it can rarely use in NPC treatment.