MET and head and neck squamous cell carcinoma: In our study, we were interested to test the hypothesis that Slug as a major EMT-transcription factor in HNSCC promotes EMT by suppressing E-cadherin and cadherin-based epithelial adhesion, whereas, KLF4, which promotes the epithelial state in opposite, presents itself as a MET-transcription factor and induces epithelial phenotype.