IAPP and Alzheimer disease: The pro-IAPPβ, pro-IAPPγ, and fs-IAPPγ in AD plasma samples were reduced to 56.5% (t(27) = 4.65, p < 0.0001), 82.0% (t(27) = 2.41, p = 0.0229), and 72.6% (t(27) = 2.42, p = 0.0224) of those in normal controls, respectively (Figure 4A–C), but we did not find significant differences (t(26) = 0.25, p = 0.8044) by IAPP-ELISA (Figure 4D).