miR-34c belongs to a family of microRNAs that are induced by p53 and cause cell cycle arrest and apoptosis, partially by targeting the expression of c-MYC.24 This miRNA also regulates multiple components of the WNT pathway, including β-catenin, and acts as a tumour suppressor miRNA in many cell types.25 Restoration of miR-34c expression leads to a decrease in the migration, invasion and metastatic potential of nasopharyngeal carcinoma cell lines.26 Notably, miR-34c is expressed in oral keratinocytes at much higher levels than in skin keratinocytes (more than 150 times; results not shown). This evidence concerns the gene MYC and neoplasm.