Modulation of cytokine signaling by SOCS proteins during inflammatory arthritis. Multiple cytokines can induce SOCS expression, which subsequently inhibits signaling by many of the same cytokines. Feedback inhibition and cross-regulation of signaling contribute to suppression of cytokine activity and attenuation of inflammatory arthritis. SOCS expression is induced as part of a feedback inhibition loop by cytokines that are pro-inflammatory (shown in red) or by anti-inflammatory cytokines such as IL-10 (shown in blue). AP-1, activator protein–1.