Elevated levels of CCL2 were found in plasma and CSF (Corrêa et al. 2011; Galimberti et al. 2006; Lee et al. 2018; Nordengen et al. 2019; Stuart and Baune 2014), and brain tissue, including critical structures for AD, such as the hippocampus, frontal, and temporal cortex of AD patients as compared to healthy controls (Liao et al. 2016; Sokolova et al. 2009). This evidence concerns the gene CCL2 and Alzheimer disease.