The studies of Meng et al. showed a correlation of miR-21 expression and gemcitabine-induced apoptosis and modulation of PTEN and associated pathways, thus affecting phenotypic characteristics such as cell growth, migration, and invasion in cholangiocarcinoma and hepatocellular carcinoma in vitro and in vivo[55], [56]. The gene discussed is PTEN; the disease is hepatocellular carcinoma.