HMGB1 and central nervous system cancer: In particular, we assessed the release of several DAMPs (ATP and HMGB1) from glioma GL621 cells after pz I-PDT or pz III-PDT in vitro and analyzed whether dying glioma GL261 cells induced by pz I- or pz III-based PDT can protect mice from tumor growth in a prophylactic subcutaneous glioma vaccination model.