5XFAD mice represent one of the earliest-onset and most aggressive amyloid models based on the overexpression of human APP and presenilin 1 (PS1) harboring five FAD mutations (Oakley et al., 2006; Ohno et al., 2006), providing a presymptomatic AD model at the young age (Figure 2A). The gene discussed is APP; the disease is Alzheimer disease.