MTOR and renal cell carcinoma: Growth factors such as vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF) and their downstream signalling pathways including phosphatidylinositol 3-kinase (P13K) and mammalian target of rapamycin (mTOR) became new targets in the crusade against RCC.