The GC_1 gastric tumor with intestinal differentiation and regions with discohesive cells showed a variation in the expression of ZO1, E-cadherin and CLDN4: Although the overall tissue organization/architecture differed for the tumor regions with intestinal differentiation with respect to the healthy gastric glands, formation of epithelial monolayers facing luminal structures and cell polarity was still detectable to a large extent. Here, CLDN4 is linked to gastric neoplasm.