PancreasEpitheliumHomeodomain ProteinsIslets of LangerhansGene Expression Regulation, DevelopmentalEpithelial CellsCell DifferentiationMice, TransgenicEpithelium, CornealSeminiferous EpitheliumRetinal Pigment EpitheliumOlfactory MucosaRespiratory MucosaIntestinal MucosaImmunohistochemistryTracheaCorneaBronchiCiliary BodyIn Situ HybridizationMicroscopy, ElectronConjunctivaNasal MucosaRNA, MessengerMetaplasiaKeratinsCells, CulturedMicroscopy, Electron, ScanningMorphogenesisOrgan Culture TechniquesMucous MembraneColonMouth MucosaEsophagusReverse Transcriptase Polymerase Chain ReactionLung