APP and Alzheimer disease: Other microglial states reported in AD pathology include the MGnD, which displays a down-regulation of homeostatic genes (e.g., p2ry12, tmem119, fcrls) and an up-regulation of genes such as apoe, clec7a, and trem2, linked to the phagocytosis of apoptotic neurons and dystrophic neurites in 24-month-old male and female APP-PS1 mice (Krasemann et al., 2017).