Immunostaining for E-cadherin. A) Immunostaining for E-cadherin in normal oral mucosa. B) Strong membranous immunostaining in the oral basaloid squamous cell carcinoma (BSCC). C) Most neoplastic cells of well to moderately differentiated squamous cell carcinoma (W/MSCC) showed strong membranous immunopositivity. D) Poorly differentiated squamous cell carcinoma (PDSCC) showed weak membranous immunostaining. (A, B, C and D, immunohistochemistry E-cadherin; original magnifications, A, B and D, ×400; C, ×100).