PTEN and hepatocellular carcinoma: Exposure of HCC cells to sorafenib results in an increase in miR‐21 expression, a decrease in PTEN expression, and sequential Akt activation, leading to upregulation and activation of mammalian target of rapamycin (mTOR) and glycogen synthase kinase‐3β (GSK3β) (He et al., 2015; Zhai et al., 2014).