APP and Alzheimer disease: In further support of a relationship between redox capacity and AD, mice heterozygote for MnSOD (resulting in oxidative stress) crossed with transgenic mice Tg19959 mice overexpressing human amyloid precursor protein (hAPP) displayed elevated Aβ levels as well as increased Aβ plaque deposition relative to Tg19959 mice alone (Li et al., 2004).