MCL1 and osteosarcoma: Chemotherapeutic agents, including methotrexate, cisplatin and doxorubicin, are widely employed in osteosarcoma treatment, but their anticancer efficacy may be hindered by anti‐apoptotic proteins such as BCL‐2, MCL‐1, c‐FLIP and XIAP [48, 49, 50, 51, 52].