In addition, CD4+ naive T cells, regulatory T cells, M2 macrophages, resting mast cells were identified as risk immune cells in digestive system cancers, while the abundances of naive B cells, CD8+ T cells, CD4 memory activated T cells, follicular helper T cells, and eosinophils were correlated with better relapse free survival (Yang et al., 2019). Here, CD8A is linked to digestive system cancer.