MTOR and renal cell carcinoma: As an intermediate regulator, a wide range of molecules contribute to RCC different malignant phenotypes via mTOR signaling pathway, including pyruvate kinase M2 (PKM2) (Dey et al., 2019), enoyl-CoA hydratase short-chain 1 (ECHS1) (Qu et al., 2020), nucleobindin-2 (NUCB-2) (Tao et al., 2020), miR-100 (Liu et al., 2020b), and maternal and embryonic leucine zipper kinase (MELK) (Zhang et al., 2019).