APP and Alzheimer disease: Furthermore, Fbs1 attenuates amyloid-β (Αβ) production through ubiquitination of β-secretase (BACE1) and amyloid precursor protein (APP), and the expression of Fbs1 decreases in the brains of Alzheimer’s disease (AD) patients and Tg2576 mice, a well-characterized model of AD (Gong et al., 2010; Atkin et al., 2014).