FIG. 7.

Extracellular HMGB1 functions as a damage-associated molecular pattern molecule signal. HMGB1 is passively released from injury and necrotic cells and is actively secreted by inflammatory cells, binding with high affinity to several receptors, including the receptor for advanced glycation end products (RAGE), Toll-like receptors (TLR)-2, TLR-4, triggering receptor expressed on myeloid cells-1 (TREM-1), and CD24, mediating the response to cell migration, cell activation, cell proliferation, and cell differentiation. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article at www.liebertonline.com/ars).