Importantly, vascular dysfunction is thought to contribute to cognitive decline in TBI, AD, and aging (Lynch et al., 2016; Nelson et al., 2016; Ojo et al., 2015; Pop & Badaut, 2011; Zhao et al., 2015), and eNOS deficiency in mice has been linked to cognitive impairment (Tan et al., 2015). The gene discussed is NOS3; the disease is Alzheimer disease.