Patterns of epithelial cells and DCAMKL1 cells in the regenerative mucosa of a healing ulcer. (a) An H&E-stained section taken at 2 weeks after acetic acid treatment, showing the regenerative tissue of the healing ulcer. Scale: 1000 μm. (b) A magnified view of the regenerative mucosa outlined in (a). A gradient of epithelial regeneration from the ulcer edge (right side) to the regenerated mucosa distant from the ulcer (left side) was identified. Scale: 100 μm. (c-h) Serial sections of (b), stained with MUC5AC (c), TFF2 (d), MUC6 (e), pepsinogen II (f), H+/K+-ATPase (g), and PCNA (h). (i) Double-color immunostaining for DCAMKL1 and TFF2 in a serial section of (b).