ICOS and colorectal carcinoma: CD8+ TILs also showed a similar pattern of IC expression as CD4+ TILs in CRC TME; PD-1 (NT; 3.5 ± 1.0 vs. TT; 22.0 ± 3.1), TIM-3 (NT; 3.7 ± 0.6 vs. TT; 18.9 ± 2.6), TIGIT (NT; 22.1 ± 1.6 vs. TT; 27.3 ± 2.6) and ICOS (NT; 3.7 ± 0.3 vs. TT; 14.9 ± 2.0) were significantly overexpressed on CD8+ TILs compared to cells isolated from NT (Figure 2C).