HMGB1 and neoplasm: We also did FASC analysis to see what percentage dead cells (necrosis and apoptosis) presented at different irradiation doses and the data showed that higher dose of irradiation induced more necrotic and apoptotic cells (S.1) Thus, we inferred that the primary source of HMGB1 from irradiated tumor cell culture medium was derived very likely from necrotic cells, which passively released the cellular content (including HMGB1) when cell membrane disrupted.