HMGB1 and cancer: Some studies on the underlying mechanism for antitumor immunity indicated that particle beam radiation has the ability to induce immunogenic cell death in cancer cells, releasing “eat me” and “danger” signals, such as calreticulin (CALR) and high mobility group box 1 (HMGB1) (49, 50), respectively, thereby promoting the activation of DCs, which ultimately activates antitumor immunity (39).