High-resolution, multiplex imaging analysis of KRT8, CLDN4 and pan-cytokeratin (PanCK) showed that KACs were enriched in tumour-adjacent normal regions (TANs) and were found immediately next to malignant cells showing high expression of KRT8 and CLDN4 (Fig. 2f and Extended Data Fig. 4a). Here, CLDN4 is linked to neoplasm.