For example, studies using the selective KOR agonist [11C]GR103545, the preferential KOR agonist [11C]EKAP, and the preferential KOR antagonist [11C]LY2795050 report high KOR blockade (85–93%) in healthy participants and participants with cocaine dependence 2–3 h after administration of 150 mg oral naltrexone [36–39]. The gene discussed is OPRK1; the disease is cocaine dependence.