HMGB2 and esophageal squamous cell carcinoma: In the ESCC group, CD3-CD56+ NK cells (p < 0.001) and CD3-CD16+CD56+ NK cells (p < 0.01) showed significantly higher HMGB2-positive rates compared to CD3-CD16+ NK cells, indicating marked upregulation of HMGB2 in these NK subsets in ESCC patients(Figure 3c).