Tau, Aβ42 and Appl (AD-related genes) are involved in the pathogenesis of AD and their ectopic expression results in several phenotypic/behavioral abnormalities such as rough eye phenotype, phototaxis and climbing defect, and reduced survival and body weight in Drosophila (Fernández-Moriano et al., 2015; Gistelinck et al., 2012; Iijima-Ando and Iijima, 2010; Peng et al., 2015; Roy and Jackson, 2014). The gene discussed is APPL1; the disease is Alzheimer disease.