Figure 3. Cldn10-positive cells with cuboidal to oval shape line the alveolar epithelium in IPF lungs. Resin-embedded lung sections from patients with IPF were labeled for Cldn10 using immunogold labeling method. Arrows in (B, C, F & H) denote Cldn10 signals. (A) Alveolar epithelium with mild fibrosis is lined by a monolayer of metaplastic epithelial cells with cuboidal to oval shape (Asterisks). (B) Cldn10 expression (arrows) are located in close proximity to the tight junction (TJ) between the two adjacent cells. Note that the the Cldn10 signals shown belong to the epithelial cell circled by arrowheads in (A). (C) Cldn10 expression (arrows) are located in the cytoplasm (Cyto) and nucleus (Nuc). Additional photomicrographs showing the spatial association of this cell with the subjacent fibroblast are presented in