CD4 and Alzheimer disease: For example, peripheral type 1 and type 17 T-helper (Th1, Th17) cells have been reported to be associated with releasing of inflammatory cytokines in multiple AD mouse models.13,14 Consistent with these evidences, peripheral infiltrated lymphocytes were observed in the brain of both transgenic mouse models and AD patients.13 Additionally, in the post-mortem brains of AD patients, both CD4+ and CD8+ T cells were detected.15