In melanoma, miR-29 expression was inversely correlated with protein levels of DNA methyltransferases DNMT3A and DNMT3B, which affected overall survival (Nguyen et al., 2011); miR-29 expression was also negatively correlated with DNMT3A and B in lung cancer, and transfection of miR-29 restored normal methylation patterns and expression of various tumor suppressor genes, as well as inhibiting tumorigenicity in vitro and in vivo (Fabbri et al., 2007). This evidence concerns the gene DNMT3A and lung cancer.