[7][8][9] Chemokines and their receptors, such as CCR9 and its binding agonist, are key regulators of thymocyte migration and maturation in normal and inflammatory conditions.

The effects of chemokines binding to their specific receptors is generally dependent on the structural placement of the N terminal cysteine(s) amino acids.

[11][8] It has been found that this gene is differentially expressed by T lymphocytes of small intestine and colon, suggesting a role in thymocyte recruitment and development that may permit functional specialization of immune responses in different segments of the gastrointestinal tract.

The breadth of effects following interactions of CCR9 and its binding ligand CCL25 are vast and not completely understood, however, it is generally thought that CCR9 and CCL25 play substantial roles in cancer proliferation and inflammatory diseases.

[12] CCR9/CCL25 interactions are known to contribute to the up-regulated migration of memory T cell homing to the gut given high expression of CCL25 in intestinal lining.

CCR9/CCL25 interaction is believed to significantly influence the cellular functions of cancer cells and ultimately contribute to their proliferation and metastasis.