The J9 model is a transgenic mouse that expresses human amyloid precursor protein (APP) with Swedish (K670N/M671L) and Indiana (V717F) mutations, which increases Aß formation and favors Aß42, the form more likely to be found in senile plaques(Hsia et al. 1999; Mucke et al. 2000). The gene discussed is APP; the disease is Senile plaques.