The CYP2C19*17 allele is assigned as an increased function allele by CPIC. Patients carrying the CYP2C19*17 allele in combination with a no or decreased function allele who are treated with clopidogrel may have an increased risk for adverse cardiac and cerebrovascular events as compared to patients with two normal function alleles. However, conflicting evidence has been reported. Other genetic and clinical factors may also influence the risk for adverse cardiovascular events.