MTOR and lung cancer: Our results suggest that T4 has a more obvious effect on the viability of A549 and A549/DDP lung cancer cells when combined with the rapamycin, wortmannin and perifosine pretreatment; PI3K is upstream of AKT and mTOR; and mTOR is downstream of PI3K and AKT in the PI3K/AKT/mTOR signaling pathway.