The mRNA levels of several inhibitory immune checkpoints, transcription factors, and other TEX-related markers are elevated in CRC tumor tissues, including PD-1, CTLA-4, TIGIT, T cell immunoglobulin, and mucin domain-containing protein 3 (TIM-3), CD160, CD244, killer cell lectin-like receptor subfamily G member 1 (KLRG1), Thymocyte selection-associated high-mobility-group box 2 (TOX2) and TOX3, gene name for Blimp1 (PRDM1), and Ki-67, while PD-1 and CD160 are downregulated in tumor tissue of advanced stages (114, 115). Here, PDCD1 is linked to neoplasm.