A recent study based on a prophylactic tumor vaccination model strongly supported that ferroptosis is a type of ICD: early, but not late, ferroptotic cancer cells (murine fibrosarcoma MCA205 or glioma GL261 cells) promoted the phenotypic maturation of bone marrow-derived DCs, and the most typical DAMPs, ATP and HMGB1, were detected along the timeline of ferroptosis (Efimova et al., 2020). Here, HMGB1 is linked to cancer.