Among the six miRNAs analyzed, the expression of miR-16 showed the highest inverse correlation with the COX-2 protein/mRNA ratio (R2 = 0.858, p = 0.016) (Fig. 1B), suggesting that miR-16 is involved in COX-2 regulation in hepatoma cell lines. This evidence concerns the gene PTGS2 and hepatocellular carcinoma.