AKT1 and nasopharyngeal carcinoma: To investigate CDDP resistant mechanism in NPC, we treated cells with CDDP and found that the phosphorylation of AKT, GSK-3β, S6K and 4E-BP1 increased in dose-dependent manners, which suggested that activation of PI3K/AKT and mTORC1 pathways was induced by CDDP (Fig. 4A).