HMGB1 and neoplasm: Extracellular HMGB1 signals through binding to receptor for advanced glycation end products (RAGE) or toll-like receptors (TLR) expressed on the surface of many cells including monocytes/macrophages, T-lymphocytes, neurons, endothelial cells, osteoclasts/osteoblasts, mesenchymal stem cells and a variety of tumor cells [17–19].