Endothelial Rap1 deficiency of both Rap1 isoforms, Rap1A and Rap1B, significantly impairs endothelial NO production in vitro and NO-dependent vasorelaxation, leading to endothelial dysfunction and hypertension in vivo (Lakshmikanthan et al., 2015). The gene discussed is RAP1A; the disease is hypertensive disorder.