A study by Abu-Farsakh found that CLDN2 expression was significantly higher in OAC, squamous cell carcinoma (OSCC), and glandular lesions compared with squamous cell carcinoma, although no significant relationships were found between tissue levels of this protein and age, gender, grade, stage, or the survival time of patients with OAC and OSCC [65]. This evidence concerns the gene CLDN2 and squamous cell carcinoma.