HMGB1 and melanoma: UV irradiation induced release of high-mobility group box protein 1 (HMGB1), a hallmark of ICD, by OVA-expressing B16 melanoma cells (B16-OVA) [28], even higher than the strong ICD-inducer doxorubicin, whereas the non-ICD inducers mitomycin C and brefeldin A [38, 39] had no effect (Fig. 2a).