PTEN and hepatocellular carcinoma: Park et al. reported that, by delivering cholesterol-modified antimiR-221 intravenously in hepatocellular carcinoma (HCC) xenografts, miR-221 expression was down-regulated, while p27KIP1, p57KIP2, and PTEN expression of miR-221 were consequently increased, thereby contributing to mouse tumor volume shrinkage and an increase in survival time [141].