Among the reported miRNAs that are downregulated in lung cancer, the miRNA-29 family (29a, 29b, and 29c) expression in lung cancer tissue is associated with DNA methyl-transferase DNMT-3A and DNMT-3B levels, two important enzymes for DNA methylation that are frequently upregulated and associated with poor prognosis [74]. Here, DNMT3A is linked to lung carcinoma.