 Melatonin is a hormone produced by the pineal gland which regulates many biological processes, such as circadian rhythms, cell growth and death, skin coloration, immunity, and energy production. Recent research suggests that melatonin may also be involved in regulating DNA methylation, which is important for controlling gene expression and plays a key role in cancer development. This review explores how melatonin may affect DNA methylation through changes in mRNA and protein levels of DNNTs and TET proteins, and suggests that it could potentially be used in combination with other epigenetic drugs as a new anti-cancer strategy. This article was authored by Kinga Linoviaca, Andre T. Slaminsky, Russell J. Ryder and others.