Pearson correlation analysis of 269 HCC samples from the TCGA dataset demonstrated significant negative correlation between both Smad2 and Smad3 mRNA transcript levels and miR-1258 expression (Smad3: r = −0.212, P < 0.001; Smad2: r = −0.313, P < 0.001) (Fig. 2e). This evidence concerns the gene SMAD2 and hepatocellular carcinoma.