Worthy of note, within the Group P-cad +ve, dedifferentiated areas showed both membranous and cytoplasmic P-cad up-regulation: well-differentiated (G1) oral carcinomas showed P-cad up-regulation, while P-cad expression homogeneously reduced in scarcely differentiated oral squamous cell carcinomas (G3), and it shifted to membranous/cytoplasmic co-localization, predominantly cytoplasmic in distribution, or alternatively was absent in a large numbers of cells. The gene discussed is CDH3; the disease is oral cavity squamous cell carcinoma.