APP and Alzheimer disease: To determine the validity of our results, we performed an external validation of WGCNA using existing microglial transcriptomic studies (Nanostring, n = 64 samples, 369 common genes per sample) of purified microglia isolated from WT and aging mice (2 mo–17 mo) as well as from mouse models of neuroinflammation (LPS treatment, experimental autoimmune encephalomyelitis [EAE]) and neurodegeneration (APP/PS1 model of AD pathology and SOD1-G39A transgenic model of motor neuron disease) [16].