ICOS and neoplasm: Activated tumor-infiltrating Tregs (CD4+Foxp3+ICOS+Ki67-; cluster 13) were also significantly reduced in both combination chemo‐immunotherapy treated groups (5-FU+ICB: 0.25 ± 0.20%; cisplatin+ICB: 0.29 ± 0.31%) compared to PBS controls (2.73 ± 1.01%; p = 0.015; p = 0.014 respectively) (Figure 3D).