CCR9 and neoplasm: The possibility that CCL25/CCR9 interaction and signaling has effects on cell function in addition to its effects in chemotaxis is supported by previous studies showing that such interaction promotes tumor cell growth via upregulation of cyclin D1 and tumor cell survival via phosphatidylinositol-3 kinase (PI3K) signaling and Bcl2/Bcl-xl upregulation (33).