TPMT and myopathy: When comparing European populations individually, the Slovenian and Czech populations completely lack individuals with high-risk genotypes for all 6 genes analyzed, namely CYP2C9, CYP2C19, CYP3A5, VKORC1, SLCO1B1, and TPMT, while there are some marked differences among populations related to high-risk SLCO1B1 genotypes related to simvastatin-induced myopathy and CYP2C19 genotypes related to inefficient activation of the platelet inhibitor clopidogrel [highest for the Polish population (7%) and the Greek population (4.5%), respectively; not shown].