In addition to the cytotoxic activities of ferroptosis inducers, ferroptosis has been found to induce immunogenic cell death with the release of immunoregulating molecules such as HMGB1[34] and ATP.[35] Ferroptotic cancer cells modulate tumor microenvironments to an immunoactive state.[36] In this study, we observed that ferroptotic stress modulates tumor‐infiltrated immunocytes in murine model and HNSCC samples. Here, HMGB1 is linked to head and neck squamous cell carcinoma.