Schematic diagram and sequence alignment of wild-type and four mutant Bcr-Abl proteins resulting from premature termination mutations. a The organization of wild-type and four mutant protein domains is shown. b Amino acid sequences are aligned and labeled in black (wild type), red (exon 7 Del), pink (exon 7 2-nt Del), green (exon 6 997C→T) and blue (exon 6 4-nt Ins). Sequence differences caused by frameshift mutations are underlined. Premature stop codons are indicated by asterisks, and the position of T315 is marked in yellow.