Moreover, it has been reported that increased IFNγ production in humans stimulates CXCL9 secretion, and we note that this cytokine was increased in challenged NSG-RA mice (in contrast to NSG-nonRA mice), suggesting the involvement of Th1 lymphocytes (Fig. S5) (Ruschpler et al., 2003). Here, CXCL9 is linked to rheumatoid arthritis.