In this study, we evaluate the histological characteristics of CD-associated small bowel dysplasia/adenocarcinoma and investigate the therapeutic potential of CDH17 and CLDN18 for tumor-targeted immunotherapies, and also whether expression of both CDH17 and CLDN18 are related to gastric differentiation using gastric MUC immunostains, MUC5AC, and MUC6. The gene discussed is CLDN18; the disease is neoplasm.