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. The gene discussed is ABCB1; the disease is breast carcinoma.