TET1 is associated with late-onset AD (LOAD), and the expression of TET1 is increased in the hippocampus of patients with preclinical AD and LOAD [47], and the exon region of TET1 (also called CXXC finger 6 [CXXC6]) has been shown to be related to LOAD [48]. This evidence concerns the gene TET1 and Alzheimer disease.