CD8 T cells, as the central theme in immunotherapy, have been reported in a large number of literatures, and it was consistently demonstrated that there is a certain positive correlation between the number of CD8 T cells and the response to immunotherapy, as well as a sharp linear trend with the survival rate of malignant tumors (Fridman et al., 2012; van Elsas et al., 2024). The gene discussed is CD8A; the disease is cancer.