An association between the expression of claudin-1, -2, -4, -5, and -7 in the tumor and control tissues and the clinicopathological parameters (UICC stage, tumor expansion, lymph node status, histological differentiation, lymphovascular invasion, age of manifestation, smoking and alcohol consumption, and claudin-dependent recurrence-free survival) was checked. Here, CLDN1 is linked to neoplasm.