The CYP2C19*1 allele is assigned as a normal function allele by CPIC. Patients carrying the CYP2C19*1 allele in combination with a normal function allele who are treated with clopidogrel may have a decreased, but not absent, risk for adverse cardiac and cerebrovascular events as compared to patients with a no or decreased function allele in combination with a normal or increased function allele or with two no or decreased function alleles. However, conflicting evidence has been reported. Other genetic and clinical factors may also influence the risk for adverse cardiovascular events.