However, considering that other anti-apoptotic genes (e.g., BIRC5 [survivin], BCL2, and MCL1), factors associated with cell proliferation/cycle (e.g., MYC and CCND1 [cyclin D1]), and cancer stemness are coordinately involved in STAT3-mediated adaptive survival of ALK-rearranged lung cancer cells, further investigations are required to elucidate the detailed mechanism. This evidence concerns the gene MCL1 and cancer.