MTOR and fibrosarcoma: KRAS encodes a small GTPase of the Ras superfamily, which activates several pathways related to cell survival and proliferation [e.g., the rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways] (Ferrer et al., 2018).