Despite DNMTs not being frequently altered somatically in lung cancers, multiple mechanisms are attributed to overexpression of DNMTs, including dysregulation of regulatory transcription factors (e.g., p53/Sp1) [48], downregulation of miRNAs (e.g., miR-101) that negatively regulate DNMTs [51], and impaired proteasomal degradation of DNMTs [52] (Figure 3). This evidence concerns the gene TP53 and lung cancer.