During AD progression, microglia gradually switched from a homeostatic state to DAM, as evidenced by specific markers (e.g., Csf1, Itgax, Cd63, Ank, Axl, Igf1, Clec7a, Tyrobp, Ctsb, Ctsd, Ctsl, Cd9, Ctsz, Ccl6, Trem2, Spp1, Lpl, Cst7, Apoe). The gene discussed is CTSB; the disease is Alzheimer disease.