MTOR and osteosarcoma: Inspired by the function of mTOR to selectively regulate translation of the HIF-1α mRNA transcript [174], as well as the activation effect of lncRNA MALAT1 on mTOR [175], Zhang et al. envisioned a MALAT1/mTOR/HIF-1α loop-mediated increase in pro-angiogenic factors in the angiogenesis process of osteosarcoma [176].