Figure 2 shows that there are significant associations of plasma p-tau181 with CSF t-tau (pre-clinical AD: β = 0.46, p = 0.001; prodromal AD: β = 0.23, p = 0.0003), CSF p-tau (β = 0.51, p = 0.0003; β = 0.26, p = 3.29E−05), CSF t-tau/Aβ (β = 0.43, p = 0.003; β = 0.21, p = 0.0008), and CSF p-tau/Aβ (β = 0.45, p = 0.002; β = 0.23, p = 0.0002) in both pre-clinical AD and prodromal AD. This evidence concerns the gene MAPT and Alzheimer disease.