DNA damage to peripheral lymphoid organs. A, B, C. DNA damage as determined by γ-H2AX immunostaining, alkaline comet assay without hOgg1 incubation, and alkaline comet assay with hOgg1 incubation, respectively, in IL-10−/− mice at 8 weeks of age and 6 months of age versus wildtype mice. MLN: mesenteric lymph node, PLN: peripheral lymph node.*: p<0.05, **: p<0.01 by two way ANOVA with Dunn’s multiple comparison test. Error bars represent SEM of 5–7 mice per group.