In the brains of AD patients, TREM2 interacts with components of senile plaques, including Aβ, lipo-, and apolipoproteins [70]; and the elevation of soluble TREM2 in cerebrospinal fluid (CSF) negatively correlated with plaque growth, cortical shrinkage, and cognitive decline [72]. This evidence concerns the gene TREM2 and Alzheimer disease.