TIGIT and colorectal carcinoma: TIGIT is overexpressed in many solid tumors, including in liver cancer [6, 7], colorectal cancer (CRC) [8–10], breast cancer [11, 12], thyroid cancer [13], lung cancer [14–16], gastric cancer (GC) [17, 18], esophageal squamous cell carcinoma (ESCC) [19], and melanoma [20, 21].