MTOR and cancer: For effective cancer therapy, PI3K inhibitors in combination with pathways targeting Akt, mTOR, RTKs (receptor tyrosine kinases), MAPK (mitogen activated protein kinase), EGFR (epidermal growth factor receptor), HER2 (human EGF receptor 2), DNA repair enzymes (Yap et al., 2015; Massacesi et al., 2016; Pons-Tostivint et al., 2017).