Effect of individual SNPs on CPB2 promoter activity. The indicated substitutions were introduced into the wild-type (wt; H1 haplotype) sequence³¹  by site-directed mutagenesis, in the context of the TAFI[−2699]-luc luciferase reporter plasmid.³¹  Reporter plasmids were transiently transfected into HepG2 cells along with an internal control plasmid (RSV-βgal) to control for differences in transfection and harvesting efficiency. At 48 hours after transfection, cytoplasmic extracts were prepared for assay of luciferase and β-galactosidase activities. The relative luciferase activity is defined as the luciferase activity per unit β-glacatosidase activity per unit volume of extract, and is expressed at a percentage of the relative luciferase acivity of the wt plasmid. The data shown are the means plus or minus SEM of 4 independent experiments. *P < .05 compared with the wt plasmid.