CD274 and infection: For the purpose, congenic CD45.1+ P14 cells were transferred into C57BL/6 recipients, which were subsequently infected with LCMV Cl13 virus and administrated with anti‐NKG2A‐blocking mAb or anti‐PD‐L1‐blocking mAb, or anti‐NKG2A/anti‐PD‐L1‐blocking mAbs or control mAb on day 30, 33, 36, and 39 after infection (Figure 6A).