IL17A and arthritic joint disease: In CIA mice, treatment with IL-27-Fc ameliorated arthritis severity and incidence as well, shown as less inflammation; less cartilage damage; reduced levels of CII-specific IgG and IgG2a, NF-ATc1+, nitrotyrosine+, LRP4+, and TCF3+ cells in inflamed joints; reduced IL-17 expression and Th17 cells; and increased CD4+CD25+Foxp3+, CTLA-4+, PD-1+, and GITR+ Tregs in the spleen (182, 183).