MTOR and renal cell carcinoma: Recent advances in our understanding of the biology of renal cell carcinoma led to the development of novel targeted therapies such as mTOR (mammalian target of rapamycin) inhibitors as temsirolimus or the inhibitors of the split-kinase-domain family of receptors of tyrosine kinase sunitinib and sorafenib, which prevent tumor angiogenesis through vascular endothelial growth factor inhibition (mTOR and VEGF are commonly used and may be explained but not substituted).