SERPINA3 and Alzheimer disease: Together, the comprehensive integrative analysis of platelet and brain omics data demonstrated that the molecular changes in platelet can well reflect the pathological mechanism of the brain in AD patients, which provides high‐confidence platelet targets for future large‐scale validation in AD‐related population (Figure 5), highlighting the key regulator role of HMOX2 and SERPINA3 in AD, as well as the potential diagnostic value of RTN1 and IDH3B.