The role of IL-6 in hepcidin up-regulation during DSS colitis. A, IL-6 mRNA levels in the colon and liver following DSS treatment for 48 hours or 7 days, expressed relative to the mean level in control mice that did not receive DSS. *p = 0.006, **p = 0.031, n = 3 mice per group. B, Liver hepcidin mRNA levels in wild-type and IL-6 knock-out (KO) mice 48 hours after starting DSS, expressed relative to the mean level in the wild-type. *p = 0.019, n = 4 wild-type mice, 6 IL-6 knock-out mice.