The family of cytochrome P450 (CYP) enzymes, which affect drug metabolism, are providing a fertile playground in the field of individualized medicine. Last week researchers published that a particular polymorphism in the gene for the CYP3A5 enzyme resulted in production of an increased amount of the enzyme and is more prevalent in some ethnic groups. But knowing the existence of different SNPs is only the first step.

Writing in Nature Genetics, researchers from St. Jude Children's Research Hospital showed a SNP within the CYP3A5 gene was associated with