MTOR and hepatocellular carcinoma: PTEN is downregulated by many miRNAs upregulated in HCC, such as miR-216a [74], miR-21 [75], miR-148a [76], miR-221/222 [72], miR-519d [77], and miR-29a [78], leading to the activation of PI3K/AKT/mTOR pathway.