Further analysis showed that DNA methylation plays an important role in ALDH2 expression, which was mediated by DNA (cytosine-5)-methyltransferase 3A (DNMT3A) and methylated CpG binding protein 4 (MBD4), and that the expression of these regulators greatly increased the probability of BM in lung cancer patients. This evidence concerns the gene ALDH2 and lung carcinoma.