Rigoni et al. (2016) confirmed that long-term use of broad-spectrum antibiotics in Rag2 (R229Q) mice can ameliorate intestinal and systemic autoimmunity by reducing mucosal and circulating gut-tropic CCR9(+) Th1 and Th17 T cells frequency. In addition, during the allergic reaction, CCL25 drives the mobilization of IL-17+ γδ T cells to inflamed tissues through α4β7 integrin, and regulates the level of IL-17 (Costa et al., 2012). The gene discussed is CCR9; the disease is allergic disease.