This book summarizes the last ten years' research on Alzheimer's disease. Genetic mutations in the gene which codes for amyloid precursor protein (APP) have now been shown to cause Alzheimer's disease in some families. Other genetic loci are now being discovered which relate to Alzheimer's disease in some families. Understanding the normal structure and function of the APP gene product will eventually provide avenues for developing specific therapeutic strategies targeted at the amyloid deposition in the Alzheimer's disease brain. Drugs which can inhibit or dissolve the amyloid, affect the synthesis and proteolysis of APP, or which regulate the activity of the APP gene all hold the promise of eventually yielding an effective treatment for Alzheimer's disease.