In cSCC tissue sections, only the poorly differentiated cells at the leading edges of the tumor express significantly lower levels of membranous E-cadherin and phosphorylated E-cadherin, and also exhibit a significant reduction in E-cadherin/β-catenin coexpression, compared to well-differentiated tumor cells, which would have been overlooked if only Western blot analysis of total protein expression was used. The gene discussed is CDH1; the disease is neoplasm.