CLDN18 and small intestine adenocarcinoma: The positive ratio of CLDN18 was also higher than that in the study on small bowel adenocarcinomas recently reported by Arpa et al. They noted that 28% of small bowel adenocarcinomas were immunoreactive for CLDN18 with a positive correlation of MUC5AC expression, using cutoff values of ≥ 1% at any intensity[26].