To extend these data to an in vivo model, we examined the induction of il-6 and two genes that are regulated by ER stress sensors, hsp5a and chop. As expected, systemic infection of C57BL/6 mice with C. muridarum caused an elevation of il-6 mRNA in the spleen within 2 days of infection (Fig. 1A). This evidence concerns the gene IL6 and infection.