In additional to the direct promotion of tumor cell growth, migration, and invasion of PD-L2+TAMs identified in our studies, the previous studies also revealed that PD-L1 and PD-L2 had similar protein structures and the affinity of PD-L2 to PD-1 was two to six-fold higher than that of PD-L1. The gene discussed is CD274; the disease is neoplasm.