MTOR and osteosarcoma: On the other hand, the previous studies showed that ALS inhibited PI3K/Akt/mTOR, p38 MAPK, or Erk1/2 signaling pathways while activating AMPK signaling pathway, contributing to the pro-autophagic effects of ALS in gastric cancer cells [19], pancreatic cancer cells [21], osteosarcoma cells [22], breast cancer cells [44], and ovarian cancer cells [19,20,21].