Because Aβ plaques are surrounded by activated microglia in AD (Kamphuis and Orre et al., 2012), we analyzed the colocalization of plaques and microglia in APP/PS1+LV‐control and APP/PS1+LV‐shNgR mice by co‐staining with anti‐Aβ (6E10) and anti‐Iba‐1 antibodies. The gene discussed is PSEN1; the disease is Alzheimer disease.