Male mice with higher arthritis activity at 21 weeks had elevated serum levels of multiple cytokines compared to less arthritic females including GM-CSF, IFN-γ, IL-1β, IL-2, IL-12, and IL-17, as well as the growth factor FGF-basic, which correlated with higher arthritic scores (Fig. 2A,C). Here, IL17A is linked to arthritic joint disease.