NOS2 and Alzheimer disease: The authors found that M2 activation genes, including arginase I (AGI), mannose receptor (MRC1) and chitinase 3-like 3 (YM1), and M1 activation genes, such as TNF-α and nitric oxide synthase 2 (NOS2), co-existed in the cortical tissues of both transgenic mouse models and AD patients (Colton et al., 2006; Bolós et al., 2017).