IL4 and Arthritis: To confirm and compare the importance of other Th2 cytokines in vivo, we developed DR1 mice that were genetically deficient in IL-4 and IL-10, so that groups of 10 IL-4-/- or IL-10-/- mice could be treated with A12 at the time of immunization with CII/CFA and compared with wild-type DR1 mice for the severity of the development of arthritis.