Identity of the mutations indicated in the diagram in Fig. 7 E. The BCR-ABL1 (exon 13 of BCR and exon 9 of ABL1) was RT-PCR amplified from single cell clones, and a fragment of ∼700 bp in the ABL1 kinase domain was directly sequenced. The number to the left of the mutation indicates the mutated position with respect to the ABL1 open reading frame. The mutated base is underlined within the affected codon. Mutations at C:G pairs and amino acid substitutions previously described to confer clinical imatinib resistance (Branford and Hughes, 2006) are highlighted in bold.