TREM2 and neurodegenerative disease: Multiple M0-homeostatic microglial transcripts were repressed in C1QC+ macrophages, including CST3, NFKB1, JUN, and EGR1, while the key transcripts of dysfunctional microglia in neurodegenerative diseases, including APOE, TREM2, and LGALS3, were strongly upregulated32 (Fig. 3d).