CTSD and Alzheimer disease: For example, DEGs associated with homeostatic state of microglia (e.g., P2RY12, CSF1R, CX3XR1, TGFBR1, MEF2A, and ENTPD1) are decreased, while DEGs associated with the dyshomeostatic state of microglia (e.g., CTSD, APOE, AXL, SPP1, and GPNMB) are increased in AD compared to the control30,38 (Fig. 4G).