In breast cancer, Zhu et al. demonstrated that the DNA methyltransferase DNMT1 induces hypermethylation of the promoter of maternally expressed gene 33 (MEG3) and inhibits its expression, which then promotes the growth of breast cancer cells through the regulation of the miR-494-3p/OTUD4 axis [66]. This evidence concerns the gene MEG3 and breast cancer.