Numerous up-regulated early MARPs, including CD74, CTSD, CTSH, CTSZ, HEXA, GLB1, CD68, NPC2 and CLN3, reflect alterations in endo-lysosomal homeostasis as an early pathological insult in AD microglia (Van Acker et al., 2019). The gene discussed is CTSZ; the disease is Alzheimer disease.