MTOR and renal cell carcinoma: Previous studies demonstrated that phosphorylated mTOR (p-mTOR) was increased in RCC, and enhanced p-mTOR was associated with impaired overall survival (OS), which indicated that the PI3K/AKT/mTOR signaling pathway could promote the initiation and progression of RCC (Darwish et al., 2013; Kruck et al., 2010; Liontos et al., 2017; Rausch et al., 2019).