Therefore, in the synovial compartment of wt and Fas −/− non-immunized (NI), immunized control (IMM) and arthritic (AIA) mice, we assessed the proportions of CD3+ T lymphocytes, considered responsible for the immune-mediated pathology, CD11b+Gr-1+ granulocytes-monocytes and F4/80+macrophages involved in the inflammatory component of arthritis (Figure 1A). Here, FAS is linked to arthritic joint disease.