Human osteosarcoma cell lines (HOS and CCK8) were purchased from Nanjing Dingsheng Biotechnology Co., Ltd. Fetal bovine serum (HyClone) was purchased from Beijing Saiaoruite Biochemical Products Co., Ltd. hTERT antibody was purchased from Santa Cruz Biotechnology; Bcl-2 antibody, DAB chromogenic reagent kit, and immunohistochemical staining kit (SP kit) were all purchased from Chengdu Hengyuan Bioengineering Co., Ltd. Here, BCL2 is linked to osteosarcoma.