Although in our hands the absence of TYROBP did not affect the total number of microglia in the cortex and hippocampus of WT or AD-related mouse models as compared to mice with WT level of TYROBP, we showed that a constitutive deficiency of TYROBP in the APP/PSEN1 mice, a mouse model of the cerebral amyloidosis of AD, reduced the clustering of microglia around Aβ plaques. This evidence concerns the gene PSEN1 and Alzheimer disease.