APOE and Alzheimer disease: Using a snRNA-seq approach on post-mortem prefrontal cortex tissue from individuals with low to high levels of Aβ burden, Mathys et al. (2019) found two main modules containing genes whose expression in microglia correlated with AD pathology, including APOE, TREM2, MHC class II, PICALM, and MEF2C (see their function in Table 1).