MTOR and osteosarcoma: In MG63 osteosarcoma cells, CQ enhances apoptotic cell death promoted by mTOR inhibitor rapamycin (RAPA) by blocking the activity of downstream molecules of Akt/mTOR pathway 4E-BP1 and p70S6k, increasing the expression of autophagy-related proteins LC3-II and Atg12-Atg5, and decreasing the p62 level [78].