IL4 and arthritic joint disease: Although the absolute levels of serum IL-17 were comparable between the groups, there was a significant correlation between IL-17 and arthritis severity in the anti-IFN-γ group but not in the anti-IFN-γ + anti-IL-4 group (we could not address the IL-17/IFN-γ ratio in these mice, as treatment with anti-IFN-γ precludes ELISA for IFN-γ in the serum).