Mice with partial eNOS deficiency (eNOS+/−) develop early hypoperfusion, progressive BBB hyperpermeability, white-matter injury, microinfarcts, and age-dependent memory impairments and show greater BBB disruption under stressors such as hypoxia or chronic hypoperfusion, with worse cognitive outcomes when eNOS is reduced or absent [112,114]. The gene discussed is NOS3; the disease is memory impairment.