FN1 and head and neck squamous cell carcinoma: Haddad and colleagues [88] used real-time quantitative PCR and immunoblotting to characterize the expression of E-cadherin, vimentin, fibronectin, and delta-crystallin enhancer-binding factor 1 (deltaEF1) across a panel of HNSCC-derived human cell lines to decipher mechanisms underlying the resistance to erlotinib.