CD8A and parasitic infectious disease: Considering only 20% T cells in liver could be detected by flow cytometry (48), it is estimated that approximately 2.5 million liver CD8+ Trm cells are required to screen 99% of the whole liver for parasite infection during a 2-day window in mouse liver-stage malaria (43).This indicated that a large amount of liver CD8+ Trm cells are required to prevent progression to the blood stage, and the optimal generation of CD8+ Trm cells in the liver could guide the design of highly effective malaria vaccines.