It is a cell cycle promoting gene with proliferative activity and is found in the epithelium; this protein is found to be up‐regulated and exhibits pro‐tumour effect by activating the HIF‐1α signalling pathway in osteosarcoma.16, 22, 23 In our study, we demonstrated that the expression of CBX4 in lung tumour tissues was significantly higher compared with adjacent cancer tissues (Figure 1A,B). The gene discussed is CBX4; the disease is cancer.