Single-nucleus RNA sequencing in the frontal cortex of AD patients with APOE ε4 alleles showed astrocytes with highly expressed APOE ε4 and markers of reactive astrocytes (GFAP, HSP1B, IFITM3, TAPBP, CHI3L1, etc.)(Table 1; Griswold et al., 2021). The gene discussed is APOE; the disease is Alzheimer disease.