However, injection of collagen-specific T cells to CAIA-induced mice prolonged the disease [39], and T-cell suppression by CTLA-4 Ig treatment [40] or CTLA-4 Ig and cyclosporine treatment [41] in a later phase of CAIA suppressed the severity of arthritis, indicating that T cells play a role in CAIA as an amplifier. Here, CTLA4 is linked to arthritic joint disease.