GPNMB and Alzheimer disease: Activated response microglia (ARMs), characterized by overexpression of MHC type II, Dickkopf-related protein 2 (Dkk2), hematopoietic growth factor inducible neurokinin-1 type (Gpnmb), and secreted phosphoprotein 1 (Spp1) [82], were identified as potential mediators of both age-, sex-, and genetic-based heightened risk for AD.