Interestingly, we found that the genes are not only associated with AD, but also presented as risk factor genes for other neurological diseases including Amyotrophic lateral sclerosis (ALS), Multiple sclerosis (MS), Parkinson's disease (PD), and Schizophrenia disease (SZ); three AD genes (ACE, TNF, and MTHFR) are associated with all four diseases, while 178 AD genes are associated with one or more of the diseases. The gene discussed is MTHFR; the disease is Alzheimer disease.