Transcriptional activity of the continuous 4-kbp regulatory region (c.-4076 to c.-1) with/without the CAR expression plasmid. The combination of variations in each expression vector is shown in Figure 1. Name of expression vector represents polymorphisms included and vector type. In the first part of the name, T and G respectively denote c.-3275T and c.-3275G. In the second part of the name, w and m refer to wild type and mutant-type region between gtPBREM and the TATA box. In the third part, (TA)6 and (TA)7 denote A(TA)6TAA and A(TA)7TAA. In the fourth part, wild, Gilbert and combination indicate that each vector has wild-type sequence, or typical mutant-type sequence in subjects suffering from Gilbert syndrome, or an artificial sequence constructed for this study. The mean transcriptional activity of the wild-type vector, T-w-(TA)6_wild, without the CAR expression plasmid was chosen as 1.00. Each column and bar represents the mean and SD of four independent determinations. The vector with typical regulatory region showing Gilbert syndrome is G-m-(TA)7_Gilbert. The open box is a wild-type region between gtPBREM and the TATA box, including ten linked polymorphisms: c.-3152G>A, c.-2951A>G, c.-2743T>C, c.-2737T>C, c.-2726G>A, c.-2724AT, c.-2473T>G, c.-1352A>C, c.-689A>C and c.-364C>T. The gray box is a mutant-type region having mutant-type sequence corresponding to the wild-type inner region. Luc is luciferase cDNA.