HMGB1 and cancer: Analysis of supernatants from MCA205 cancer cells stimulated with ML162 and two other ferroptosis inducers, RSL-3 (class II) and Erastin22 (class I, relying on the blockage of the cystine–glutamate antiporter system Xc−) (Supplementary Fig. 1a–c) reveal the presence of DAMP including ATP and HMGB1 as well as cytokines including CXCL1, TNF, and IFN-β (Fig. 1b, Supplementary Fig. 2a).