HMGB1 and neoplasm: In addition to releasing “neoantigens” generated by radiation-induced DNA and protein damage through ROS production, tumor cells also release damage-associated molecular patterns (DAMPs) after IR, including high mobility group 1 (HMGB1), heat-shock proteins (HSP) and calreticulin (CRT), which mediate phagocytosis of antigen-presenting cells (APC) and initiate tumor-specific T-cell activation.