Selective APOE4 Degradation via Proteolysis Targeting Chimeras (PROTACs)

**Molecular Mechanism and Rationale** The apolipoprotein E gene (APOE) exists in three major isoforms—APOE2, APOE3, and APOE4—differing by single amino acid substitutions that profoundly impact protein structure and function. The APOE4 variant, present in approximately 25% of the population and 65% of Alzheimer's disease patients, represents the strongest genetic risk factor for late-onset Alzheimer's disease, increasing risk by 3-fold in heterozygotes and 12-fold in homozygotes. The structural...