The recruitment of monocyte-derived macrophages to the brain [15, 49] can lead to reduced AD pathology [5, 8, 21–28, 30] by removing misfolded proteins including Aβ and Tau [21, 57, 58], balancing the local inflammatory milieu [24, 58], reducing gliosis [59], and protecting synaptic structures [24, 60, 61]. This evidence concerns the gene MAPT and Alzheimer disease.