SYK and arthritic joint disease: We also determined their efficacy in standard acute arthritis models in mice; namely the collagen-induced arthritis (CIA) model, which strongly relies on T cell function and therefore eases the study of JAK inhibition (ED50 (JAK) approximately 11 mg/kg QD), and the collagen antibody-induced arthritis (CAIA) model for SYK inhibition, as it requires processing of anti-type II collagen antibodies and immune complexes via FcR.