Imatinib, whose uptake has been shown to depend on OCT1[77], is a potent inhibitor of the BCR-ABL tyrosine kinase and has therefore been used in the treatment of chronic myeloid leukemia (CML), where this aberrant fusion protein is very frequent (> 95% of cases). This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.