Recently one of the largest miRNA clusters with 53 miRNAs in the forward strand and one (miR-1247) in the reverse strand was found in DLK1-DIO3 genomic region, and many of those miRNAs are differentially expressed in several pathologic processes and various cancers.16 Moreover, emerging evidence has confirmed that the silence and low expression of some miRNAs in this cluster are regulated by the methylation of DLK1-MEG3 intergenic DMR (IG-DMR) and MEG3-DMR.17, 18 Interestingly, miR-323a-3p and previous identified miR-433 and miR-409 are all transcribed from this cluster. This evidence concerns the gene DIO3 and cancer.