APP and familial Alzheimer disease: Importantly, all research performed so far on the effect of peripheral inflammation on AD pathology is performed in mouse models that overexpress the Aβ precursor protein (APP) in combinations with different familial AD (FAD) associated mutations in APP or presenilin 1 (PS1), such as Tg2576, APP/PS1, 5xFAD and 3xTg-AD [53].