HMGB1 and neoplasm: ICD is a specific form of regulated cell death in which stressed and dying tumor cells emit danger-associated molecular patterns (DAMPs) including the exposure or release of calreticulin (CALR), ATP, annexin A1, high mobility group box 1 (HMGB1) and type I interferons that engage pattern recognition receptors (PRRs) expressed on antigen-presenting cells (APCs), such as LDL-related protein 1, formyl peptide receptor-1, purinergic receptors (P2Y2 and P2RX7), Toll-like receptor 4 and type 1 IFN receptors (IFNARs), respectively.