Between November 2021 and October 2022, Ishihara et al. (2024) from Aichi Cancer Center Hospital in Nagoya, Japan, studied serum samples collected 1 day before NIR-PIT and 1–3 days after the treatment to track changes in DAMPs (calreticulin, Hsp70, ATP, HMGB1, etc.), whose appearance on the surface of dying cells or in the TME helps determine whether cell death is immunogenic. Here, HMGB1 is linked to cancer.