A large number of epidemiological and clinical studies have shown that CYP2C19 gene polymorphism is associated with the efficacy of drugs metabolized by the enzyme, such as clopidogrel, proton pump inhibitors.By detecting the genotype of CYP2C19 in vivo, we can judge the type of metabolic rate of drugs in patients, so as to provide a reference for clinicians to adjust the dosage of drugs reasonably.