CD8A and colorectal cancer: Furthermore, studies pointed out that tumor infiltrating lymphocytes (TILs), especially CD8+ T cell density, are closely related to the prognosis of colorectal cancer, and the prognostic predictive value of immune score based on the proportion of tumor immune cells is even higher than TNM stage and microsatellite instability status in early to mid-stage colorectal cancer, but the predictive value of immunotherapy efficacy in advanced intestinal cancer is unclear (8).