Through TMT‐MS, we characterized core proteins associated with AD pathology, including amyloid precursor protein (APP) and the microtubule‐associated protein tau (MAPT), revealing a clear correlation of APP and MAPT levels with Consortium to Establish a Registry for Alzheimer's Disease (CERAD) and Braak stages. The gene discussed is APP; the disease is early-onset autosomal dominant Alzheimer disease.