CDX1 is an intestine-specific transcription factor that functions as a key regulator of intestinal epithelial cell identity and differentiation. As a sequence-specific DNA-binding transcription factor, CDX1 binds preferentially to methylated DNA and acts as a transcriptional activator through RNA polymerase II 1. CDX1 plays critical roles in intestinal zonation, where it cooperates with other factors to control metabolic domain identity and regulate genes governing lipid absorption across the small intestine 2. In colorectal cancer, CDX1 functions as a tumor suppressor by suppressing cancer stemness; specifically, CDX1 and CDX2 cooperatively inhibit β-catenin-facilitated formation of active RNA polymerase II complexes at the LGR5 promoter, thereby reducing expression of cancer stemness-related genes 3. At the mechanistic level, CDX1 reduces colon cancer cell proliferation by suppressing cyclin D1 gene transcription, leading to G0/G1 cell cycle arrest through hypophosphorylation of retinoblastoma proteins 4. Clinically, reduced CDX1 expression in colorectal adenocarcinomas correlates with dedifferentiation and malignancy 5. Additionally, CDX1 is involved in intestinal metaplasia development in the stomach and esophagus, suggesting its role in epithelial transition and differentiation processes 5.