Alzheimer's disease (AD), the most common form of dementia, is rapidly becoming a major global health concern among the elderly. Multiple pathogenic components and abnormalities in the behavior of various cell types within the CNS play a role in AD pathogenesis. The most well-studied form of neurodegenerative amyloidopathy is Alzheimer's disease (AD). Molecular pathology, aided by genomes and proteomics, is improving our understanding of neurodegenerative disease development, diagnosis, and treatment. The goal of molecular pathology is to uncover disease mechanisms by identifying molecular and pathway changes. The use of old and novel tools established in biochemistry, cell biology, molecular biology, proteomics, and genetics to the evaluation of pathological processes is at the heart of this still-evolving science. The value of molecular pathology as a supplement to histopathology in nonclinical drug development is well understood in the pharmaceutical industry.