The impact of MRP polymorphisms on ALL outcome and transcription. (A) EFS curves for TC-1393, CA934, and combined MRP genotypes. Three groups are distinguished: group 1, with TC-1393 and CC or AC934 genotypes; group 2, with TT-1393 and CC934 genotypes; and group 3, with TT-1393 and AC934 genotypes. The genotype and the number of patients in each curve, numbers of persons with an event (in parentheses), as well as the P value, estimated by log-rank test for the survival differences between the patients groups, are indicated on each plot. Times to event were measured as the time between diagnosis and the event of interest; for censored cases, it corresponded to time between diagnosis and the study endpoint (5 years after treatment, ie, 84 months after diagnosis) or to the last observational period. Risk of event associated with the given genotype, expressed as univariable hazard ratio (HR) with 95% CI estimated by Cox regression analysis, is indicated below the plots. Similar results as those shown for EFS were obtained for disease-free survival (P ≤ .02). A similar, but not significant, trend was observed for overall survival for persons with the TC-1393 genotype (P = .07), whereas there was no association for AC934 genotype (P = .4). (B) Relative promoter activity and mRNA levels in lymphoblastoid cell lines in relation to MRP promoter haplotypes. Relative promoter activity (mean ± SD) obtained by luciferase reporter assay for MRP haplotypes *A, *B, and *C is represented by , □, and ■, respectively. Empty vector is represented by a light gray bar. The values are given for 3 different cell lines, Human placental Jeg-3, cervical cancer HeLa, and hepatoma HepG2 (ATCC). The difference in promoter activity obtained by Student t test (*p) between haplotype *C and remaining haplotypes (*A or *B) is indicated on the plot. MRP expression derived from wide-genome expression dataset GSE1726²¹  is presented. The mean value of expression with 95% CI, the number of persons represented by each line, and P value obtained by analysis of variance for the difference of expression between indicated genotypes, taken from HapMap data²⁴  are given on the plots.