CCL25 is a C-C motif chemokine with specialized roles in mucosal and intestinal immunity. Its primary function is recruiting CCR9-expressing T cell subsets to the small intestine, where these cells help control intestinal inflammation 1. CCL25 demonstrates chemotactic activity on thymocytes, macrophages, and dendritic cells but not on peripheral blood lymphocytes or neutrophils, indicating tissue-specific immune regulation. The chemokine binds to CCR9 as its primary receptor and to atypical chemokine receptor ACKR4, mediating beta-arrestin recruitment 1. In asthma pathophysiology, CCR9/CCL25 signaling regulates memory-like intestinal group 2 innate lymphoid cells (ml-ILC2s) residing in the small intestinal lamina propria; these cells relocate to airways upon antigen re-exposure, promoting asthma relapse 2. CCL25 also plays roles in inflammatory bowel disease, where ectopic expression on vascular endothelium has been documented in IBD-related primary sclerosing cholangitis 3. In cancer biology, CCL25/CCR9 overexpression is associated with tumor proliferation, invasion, migration, and drug resistance across multiple malignancies 4. Additionally, CCL25 has been identified as a protein associated with nonendometrioid endometrial cancer subtypes in multiomics analyses 5. These findings suggest CCL25 as a potential therapeutic target for controlling mucosal immune responses and cancer progression.