CD274 and cancer: PD‐1/PD‐L1 upregulation was also observed in tumor (Figure 10B) and spleen (Figure 10C) tissues from mice treated with QTPlus‐AM21 which corresponds with the results that QTPlus‐AM21 could induce PD‐1/PD‐L1 upregulation in human cancer cell lines (Figure 2) and macrophage cell lines (Figure 5A,B).