Furthermore, mild cognitive impairment (MCI) represents the prodromal stage of AD (Reas et al., 2023), and previous studies indicated that male ApoE-ε4 carriers with MCI exhibited higher levels of amyloid deposition in the older age group, while female ApoE-ε4 carriers with MCI showed increased amyloid deposition in the younger age group (Wang J. et al., 2023). The gene discussed is APOE; the disease is Alzheimer disease.