A protein that is thought to regulate important activities in the body and brain by inhibiting specific enzymes and interacting with certain body cells. PN-II is formed from a precursor molecule known as beta-amyloid, via metabolic processing of the betaamyloid. Recent research indicates that incorrect metabolic processing of beta-amyloid by the body results in amyloid plaques in the brain. The amyloid plaques are generally found in victims of Alzheimer’s disease, and directly correlate (in number) with the degree of dementia.