First, in BALB/c Rag2−/−γc−/− mice engrafted with PD-L1-overexpressing and PD-L1-knockout CT26 murine colon cancer cells, Gordon et al. found that after 3 weeks, tumors were significantly smaller in the PD-L1-knockout group than in the PD-L1 overexpression group [121]. The gene discussed is CD274; the disease is malignant colon neoplasm.