APOE and Alzheimer disease: A total of 16 patients diagnosed with Alzheimer's dementia (AD) and 16 cognitively normal controls (NCs) were recruited to compare their plasma biomarkers, AβO, Aβ<sub>1-40</sub>, and Aβ<sub>1-42</sub>, also referring to other parameters like APOE ε4 status, Clinical Dementia Rating<sup>®</sup>-Sum of Boxes (CDR<sup>®</sup>-SB), and Mini Mental Status Examination (MMSE) scores.