This study found that macrophage M1 was positively correlated with immune checkpoints PDCD1, CD274 (PD-L1), PDCD1LG2, CTLA4, and TIGIT (Figure 3(c)), suggesting the opportunity of ICBs therapy in osteosarcoma patients with high infiltrating macrophage M1. The gene discussed is PDCD1; the disease is osteosarcoma.