The results showed that T4 markedly reduced the activity of P13K and AKT, upregulated the expression of LC3II, and markedly affected the phosphorylated products of PI3-K, PI3-P, AKT, TSC2, mTOR, p70S6K and 4E-BP1 in A549 lung cancer cells, suggesting that T4-induced autophagy was closely correlated with the PI3K/AKT/mTOR signaling pathway and that T4 decreased the expression of MDR1 to improve the cisplatin sensitivity of A549/DDP cells. The gene discussed is RPS6KB1; the disease is lung carcinoma.