Significant higher cathepsin D, immunoglobulin E (Chen et al., 2020), neuropilin-1, angiopoietin-2 (ANG-2), coagulation factor XI (FXI), epidermal growth factor receptor (EGFR), vascular endothelial growth factor A (VEGFA), intercellular adhesion molecule 1 (ICAM-1), matrix metalloproteinase-9 (MMP-9), von Willebrand factor (vWF), haptoglobin, and p-Tau181 levels were found in the serum samples of AD subjects than in the samples of controls (Figure 2). The gene discussed is CTSD; the disease is Alzheimer disease.