Induced autoimmune animal models of RA, including collagen-induced arthritis (CIA), glucose-6-phosphate isomerase (G6PI)-induced arthritis, and proteoglycan (PG)-induced arthritis (PGIA), are known to involve major histocompatibility complex (MHC) II-restricted antigen (Ag) presentation and generation of T cells and autoAbs that cross-react with self-(auto)Ags such as mouse type II collagen (CII), G6PI, and mouse PG (mPG) [6-10]. Here, GPI is linked to arthritic joint disease.