Fig. 1.

CYP3A4 (A) and CYP3A7 (B) promoters and known regulatory regions. The major regulatory regions, the CLEM4, XREM, C/EBPβ, and proximal promoter are expanded, with transcription factor binding sites indicated. AP1, activator protein 1; HNF4, hepatocyte nuclear factor 4; KLF9, Kruppel-like factor 9; NF1/HNF3, nuclear factor 1/hepatocyte nuclear factor 3; PAR, proline acid rich factor; PXR, pregnane X receptor; Sp/XKLF, sephacryl phosphocellulose/Kruppel-like factor; AP1, activator protein 1; USF1, upstream factor 1.