CTSB and Alzheimer disease: Compared to HOM, DAM showed up-regulation of numerous genes, including well-known AD risk factors such as Apoe, Ctsd, Lpl, Trem2, and other genes such as Igf1, Csf1, Lgals3, Cd9, Ctsb, Gpnmb, Itgax, Axl, Ctsb, Cd68, and Timp2 (Fig. 2G and Table S8).