Although CCR9 has been mostly related to immune subpopulations recruited to the small intestine, both under homeostatic and inflammatory conditions [25], we cannot exclude the possibility that CCR9 could be involved in CRC, as this cancer is highly associated with inflammation, and CCR9−/− mice develop a severe colitis phenotype, potentially predisposing them to CRC development. This evidence concerns the gene CCR9 and colorectal carcinoma.