In premalignant lesions of skin tumours, P-cadherin and α6β4-integrin are overexpressed and the expression of E-cadherin is down-regulated [82], whereas in prostate cancer and in oral squamous cell carcinoma, E-cadherin and β4-integrin are markedly loss in primary and metastatic lesions, although the mechanistic pathways were not explored [83, 84]. The gene discussed is CDH1; the disease is oral cavity squamous cell carcinoma.