HMGB1 and cancer: First, radiation induces endogenous damage-associated molecular pattern (DAMP) molecules also known as alarmins and may include intracellular proteins, like heat-shock proteins, high-mobility group box 1 (HMGB1) and proinflammatory S100 proteins linked to inflammation and cancer [16] or non-protein molecules like ATP [17], uric acid [18], heparin sulfate and DNA [19].