MDR1 polymorphisms in 90 CML patients treated by imatinib. (A) Derived haplotype from MDR1 polymorphisms and their frequency. Seven different haplotypes were defined by the 3 polymorphisms 1236C>T, 2677G>T/A, and 3435C>T. Haplotypes 1, 2, and 4 were subdivided in panels A and B according to the 3435 polymorphism. (B-F) Proportion of patients with and without major molecular response (MMR) after 12 months of imatinib (B,C,E) or with a trough imatinib plasma level (C_min) less than or more than 1000 ng/mL (D,F), according to indicated MDR1 genotypes or haplotypes. In panels B, C, and E, black represents MMR after 12 months of imatinib; gray, no MMR after 12 months of imatinib. In panels D and F, black represents C_min more than or equal to 1000 ng/mL; gray, C_min less than 1000 ng/mL. Respective genotype/haplotype, number of individuals, as well as P values are indicated on each plot. Odds ratio (OR) with 95% confidence interval (CI) in panels C and E represent risk of not achieving MMR associated with the indicated genotype.