Results: Actinic cheilitis (low grade intraepithelial squamous cell carcinoma), and the invasive front of superficially invasive squamous cell carcinoma and in situ squamous cell carcinoma were negative for claudins −1, −3 and −7. Claudin −5 was present on all epithelial layers in most cases evaluated. Claudin −11 was present in all epithelial layers in actinic cheilitis, but negative in cases of superficially invasive and deeply invasive squamous cell carcinoma.