To evaluate whether variations in disposition of docetaxel because of ABCB1 polymorphisms could be involved in the response variability of breast cancer patients, the pharmacokinetics of this drug and inherited polymorphisms of ABCB1 gene including T-129C, A61G, C1236T, G2677T/A and C3435T polymorphisms were analysed. This evidence concerns the gene ABCB1 and breast cancer.