APP and amyloidosis: To assess how Arg1 insufficiency in myeloid cells impacted amyloidosis, we crossbred LoxP Arg1 (Arg1fl/fl) mice with transgenic APP Tg2576 mice (APP+/−) to generate APP(+/−)/Arg1(fl/−) and APP(−/−)/Arg1(fl/−) (non-transgenic, nTg) mice.