Many susceptibility genes preferentially expressed in microglia of the aged human brain (e.g., TREM2, CD33, SORL1, and INPP5D) were associated with AD (Olah et al., 2018), while genetic analysis also indicated that various immune-related genes were associated with AD risk (Karch and Goate, 2015). This evidence concerns the gene INPP5D and Alzheimer disease.