Together, these data suggest that lower ACE could lead to more Aβ accumulation in the brain, reflected by lower CSF Aβ, and support previous reports that higher ACE levels, through degradation of Aβ, may contribute to less accumulation of Aβ into senile plaques in the brain and subsequently be beneficial for the occurrence of brain atrophy. The gene discussed is ACE; the disease is Brain atrophy.