In conclusion, we measured dampened and delayed inflammation in a murine model of arthritis in IRAK3-replete mice, as evidenced by reduced IL-1β and higher IL-5 levels in the plasma and more Tregs in draining lymph nodes and spleens; higher immune cell infiltration was suggested by the gene expression profiles in the affected joints of IRAK3−/− mice. Here, IL5 is linked to arthritic joint disease.