In addition, macrophages and B cells upregulated PDL1 and PDL2 in the early infection phase, and in the late infection phase, the expression level of PD1 in CD8+ T‐cells was increased.[55] With the development of immune checkpoint blockers (ICBs), PD1, as the most popular target, has been extensively applied in antitumor therapies. Here, CD8A is linked to infection.