Lujambio et al. analyzed the miRNA expression profile of three metastatic cancer cell lines with and without the DNMT inhibitor 5-aza-2’-deoxycytidine and reported that the DNA methylation of three miRNAs (mir-9, mir-34b/c, and mir-148a) was associated with the metastasis of human cancers including lung cancer (Lujambio et al., 2008). This evidence concerns the gene DNMT1 and lung cancer.