Melatonin not only control the metabolism of beta-amyloid precursor protein and several other essential housekeeping genes within different types of cells, stimulates the initial stage of neuronal differentiation, but it also significantly reduces the level of both shorter and longer forms of toxic cortical amyloid beta, which are implicated in the Aβ plaques accumulation which is a hallmark of AD [61, 62]. The gene discussed is APP; the disease is Alzheimer disease.