The brains of persons with ALZHEIMER'S DISEASE are characterised by numerous clumps of a protein – beta amyloid – known as amyloid plaques. It has been hypothesised that a genetic anomaly in processing of a naturally occurring substance in the brain, amyloid precursor protein (APP), leads to the accumulation of molecules of beta-amyloid. These sticky protein fragments are believed to trigger the damage to neurons that cause Alzheimer's Disease. Much research effort is being expended on designing MONOCLONAL ANTIBODY DRUGS or other BIOLOGICS targeted on the production or stability of beta amyloid.