EPHB3 and arthritic joint disease: Supporting a certain reduction in the immune reactivity of EphB-deficient mice, the serum antibody titers were statistically higher in WT mice that developed arthritis than in EphB3−/− CIA mice, and particularly, than in mutant mice unable to induce arthritis, such as both EphB2−/− non-CIA and EphB3−/− non-CIA mice (Fig. 7b).