DKK2 and Alzheimer disease: We further found that DKK2 expression status had no effect on TREM2 expression levels per DAPI+/TREM2+/P2RY12+ microglial cell in control (DKK2+: 0.8 ± 0.3 μm2; DKK2–: 0.6 ± 0.3 μm2), pathologic aging (DKK2+: 0.9 ± 0.9 μm2; DKK2–: 0.7 ± 0.2 μm2), and AD individuals (DKK2+: 0.5 ± 0.2 μm2; DKK2–: 0.4 ± 0.2 μm2; Extended Data Fig. 6-1B; one-way ANOVA, p = 0.2349z).