CYP2C19 and Stroke: Patients with coronary heart disease or stroke who are receiving clopidogrel and concomitant proton pump inhibitor (PPI) therapy while inheriting loss-of-function alleles (CYP2C19*2 or CYP2C19*3) had a 63% higher risk of developing major cardiovascular adverse events (Biswas et al., 2021).