Table 1. Contributions of four major determinants to the variability in mRNA levels of P450 genes.
Global Regulators1 | P450-specific Regulators2 | Environmental Factors3 | Cis-acting Genetic Variants4 | |
CYP1A1 | ** | NS | **** | * |
CYP1A2 | *** | * | **** | * |
CYP2C9 | **** | *** | *** | NS |
CYP2C19 | ** | ** | *** | * |
CYP2D6 | * | ** | NS | *** |
CYP3A4 | *** | ** | *** | NS |
CYP3A5 | *** | NS | NS | *** |
NS denotes not significant. The number of asterisks (*) corresponds to the degree of contribution by different determinants.
: The number of asterisks (*) was determined based on the correlation coefficients between the mRNA level of GAPDH and that of each P450 gene (one asterisk for a rho score of approximately 0.2).
: The number of asterisks (*) was determined based on the correlation coefficients between the mRNA levels of P450 regulator genes and that of each P450 gene (one asterisk for a rho score of approximately 0.2).
: The number of asterisks (*) was determined by the correlation coefficients between the mRNA levels of P450 genes under coregulation (one asterisk for a rho score of approximately 0.2).
: The number of asterisks (*) was arbitrarily determined based on the allelic expression ratios (for CYP1A1, CYP1A2 and CYP2C19) or the correlation coefficients between the mRNA level and copy number or some SNPs (for CYP2D6 and CYP3A5).