Importantly, previous studies demonstrated that SUV39H1 [8,9] and SETDB1 [10,11] are highly expressed in lung cancer, and the dysregulation of SUV39H1 and SETDB1 accelerates the development of lung cancer [9,11], suggesting that aberrant H3K9 methylation plays a critical role in lung carcinogenesis. This evidence concerns the gene SETDB1 and lung cancer.