Primary antibodies used were against: E-cadherin (M. Takeichi, Kyoto University, Japan); α-catenin, β-catenin, pMAPK, tubulin (Sigma, St. Louis, Missouri, United States), Ajuba (G. Longmore, Washington University, St. Louis, Missouri, United States); β4 integrin/CD104 (BD Pharmingen, San Diego, California, United States), laminin 5 (R. Burgeson, Harvard University, Cambridge, Massachusetts, United States), K5, K1, loricrin (Fuchs Lab), involucrin, fillagrin (Covance, Berkeley, California, United States), MAPK, pSMAD2 (Cell Signaling, Beverly, Massachusetts, United States); Grb-2 (Santa Cruz Biotech, Santa Cruz, California, United States); P-cadherin (Zymed Laboratories, South San Francisco, California, United States); HA (Roche Biochemicals), vimentin (Chemicon, Temecula, California, United States), Ki67 (Novo Castra, Newcastle Upon Tyne, United Kingdom), keratin 6 (P. Coulombe, John Hopkins University, Baltimore, Maryland, United States), cyclin D (Oncogene, San Diego, California, United States), and TGF-β2 (L. Gold, New York University, New York, New York, United States).