In contrast, the tumor sections from the BNCT group showed localization of HMGB1 in both the nuclei and the surrounding cytoplasmic regions in the cells, especially those with a larger size and irregular nuclear morphology (Figure 4F), where pyknotic cells were abundantly observed, suggesting HMGB1 release in the cytoplasm from dying/dead cells. This evidence concerns the gene HMGB1 and neoplasm.