CBX4 and osteosarcoma: Recently, evidence has revealed that CBX4 is a cell cycle inhibitor gene of proliferative activity in the epithelium.22 Under normoxic conditions, CBX4 acts as an up‐regulated protein with a pro‐tumour effect by activating the HIF‐1α signalling pathway in osteosarcoma.23 In addition, CBX4 is a new therapeutic target for hepatocellular carcinoma, as high expression of this protein leads to poor overall survival.17, 24 In general, researchers proved that CBX4 plays an important role in the occurrence and development of tumours.