A series of signaling pathways initiate or regulate autophagy cascades, including the adenosine monophosphate–activated protein kinase (AMPK-)–mammalian target of rapamycin complex 1 (mTORC1), class I PI3K, Akt–mTOR, Ras–rapidly accelerated fibrosarcoma (Raf-1-)–mitogen-activated protein kinase 1/2 (MEK1/2-)–extracellular signal–regulated kinase 1/2 (ERK1/2,) and p53 signaling pathways [92]. Here, MTOR is linked to fibrosarcoma.