APP and Alzheimer disease: To examine the effects of targeting miR-155 on MGnD versus homeostatic microglial phenotype expression, we crossed double transgenic APPSWE/PS1L166P mouse models of AD (herein, APP/PS1 mice) with miR-155 fl/fl and Cx3cr1CreERT2 mice to achieve tamoxifen-inducible miR-155 knock-out specifically in the microglia.