Similarly, an in vitro study showed that purified RJ peptides (RJPs) (1–9 μg/mL) can interfere with the process of Aβ formation and prevent the external production of Aβ1-40 and Aβ1-42 in N2a/APP695swe cell cultures (which produce high levels of APP in AD, because they are stably transfected with the human APP gene) via down-regulation of β-secretase [115]. This evidence concerns the gene APP and Alzheimer disease.