There is no evidence (systematic reviews and meta-analyses) on EMT in OLP, nor on the molecular events that occur in it (loss of E-cadherin, vimentin expression, expression of the transcription factors mentioned); on the other hand, there are very few primary-level studies on these aspects, so that their number would not allow the performance of meta-analyses with solvency. This evidence concerns the gene CDH1 and oral lichen planus.