CD68 and Alzheimer disease: Immunofluorescent staining of ionized calcium-binding adapter molecule 1 (IBA1, a microglia marker 26), cluster of differentiation 68 (CD68, highly expressed in activated microglia 27-29), microtubule-associated protein 2 (MAP2, a neuron marker 30) showed more activated microglia cells and less neurons in AD mice than that in WT mice (Figure 1D-E, 1J-K).