TLR2 and Alzheimer disease: A previous study analyzing brain gene expression profiles of immune-related genes in aging and Alzheimer’s disease (AD) showed that TOLLIP was downregulated in the brains of aged subjects and AD compared to the brains of young subjects, whereas genes reflecting activation of microglia such as CD14, TLR2, and TLR4 were upregulated in the brains of aged subjects and AD.