CDH2 and head and neck squamous cell carcinoma: Although it is highly controversial as to whether the EMT is indispensable for cancer metastasis [6,7,8,9], there is mounting evidence of EMT in HNSCCs: by means of multi-omic analyses, EMT or partial EMT, it was found in several subtypes of HNSCC, with alterations of multiple EMT-related molecules including E-cadherin, N-cadherin, vimentin and ITGA6 [10,11,12,13,14,15].