To investigate the role of 8-oxoG accumulated in DNA during the development of AD, we introduced Mth1/Ogg1 null alleles into homozygous triple-transgenic AD model mice (3xTg-AD-H), which carry homozygous APPSwe and MAPTP301L transgenes and a homozygous Psen1M146V-knockin mutation29. The gene discussed is NUDT1; the disease is Alzheimer disease.