FIG. 1.

The HO-1/IL-10 axis. Evidence supports the involvement of HO-1 in both IL-10 receptor signaling and signals mediated by the MyD88-independent TLR4 pathway. The main control points appear to be STAT-3 and IRF-3, respectively, although the precise mechanisms of control remain to be addressed experimentally. See text for a discussion of these pathways. HO-1, heme oxygenase-1; IL, interleukin; IRF-3, interferon regulatory factor-3; MyD88, myeloid differentiation factor 88; TLR, toll-like receptor; STAT-3, signal transducer and activator of transcription-3.