In agreement with our data showing the increased activation of circulating CD4+ T cell helper lymphocytes in 3xTg-AD mice, recent studies have shown these animals have higher serum levels of IL-2, TNFα, IL-17 and GM-CSF at 9 months of age compared with controls, suggesting the increased activation of CD4+ T cells with Th1 and Th17 phenotypes in 3xTg-AD mice40. Here, CD4 is linked to Alzheimer disease.