An ongoing phase 3 prospective multicenter double-blinded randomized controlled trial, a comparison of anti-coagulation vs. antiplatelet therapies for intracranial vascular atherosclerosis (CAPTIVA), was designed to compare low-dose rivaroxaban plus aspirin to the best DAPT (clopidogrel + aspirin or ticagrelor + aspirin according to the CYP2C19 genotype testing) in symptomatic 70–99% intracranial stenosis (ICAD) for preventing one-year recurrent ischemic stroke. Here, CYP2C19 is linked to ischemic stroke.