The CYP2C19*1 allele is assigned as a normal function allele by CPIC. Patients carrying the CYP2C19*1 allele in combination with another normal function allele may have increased metabolism of voriconazole 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. Patients carrying the CYP2C19*1 allele in combination with another normal function allele may have decreased metabolism of voriconazole as compared to patients with a normal function allele in combination with an increased function allele or two increased function alleles. However, conflicting evidence has been reported. However some studies showed no association. This annotation only covers the pharmacokinetic relationship between CYP2C19 and voriconazole and does not include evidence about clinical outcomes. Other genetic and clinical factors may also influence metabolism of voriconazole.