APP and Alzheimer disease: This microglial pathology in AD and even in Down syndrome brains has been previously reported (Lopes et al., 2008; Streit et al., 2009, 2014; Xue and Streit, 2011), however, it has never been detected in APP-based models (Figure 1; Jimenez et al., 2008; Heneka et al., 2015).