PDCD1 and colorectal carcinoma: Interestingly, we found significantly lower levels of PD-1 in advanced stage CRC (A;16.2 ± 3.0 vs. E; 26.0 ± 3.6), TIM-3 (A; 12.6 ± 2.4 vs. E; 20.3 ± 3.0) and TIGIT (A; 23.9 ± 2.6 vs. E; 31.2 ± 3.0)-expressing CD8+ T cells in the TME compared to CRC patients with early stage disease.