Analysis of TCGA database using the Cancer Regulome tool showed that the expression of the most highly upregulated miRNAs in PTC—miR-146b-5p, miR-146b-3p, miR-21-3p, miR-21-5p, miR-221-3p, and miR-222-3p—negatively correlated with DICER1 mRNA levels (Fig. 1a). This evidence concerns the gene DICER1 and cancer.