APP (Amyloid Precursor Protein): APP is a measure that reflects the role of a key transmembrane protein involved in various cellular processes, especially in the central nervous system. APP is essential for neuronal development, synaptic plasticity, and cell signaling. Its processing produces amyloid-beta peptides, which are linked to the development of Alzheimer's disease. Proper regulation of APP processing and amyloid-beta production is critical for maintaining neuronal health and cognitive function, while dysregulation can contribute to Alzheimer's pathology.