INS and Alzheimer disease: There may be several reasons for such repeated failure: (1) Treatment for AD is typically initiated late in the pathophysiological process; (2) Alzheimer’s disease is not a single disease but rather exhibits several different subtypes; and (3) AD is a complex chronic condition, and there are several potential contributors to AD, such as inflammation, various chronic pathogens, trophic withdrawal, insulin resistance, vascular defects, trauma, and exposure to specific toxins [2,15,16,18,19,22].