Sequence alignments between e1a2 (p190) and the variant e1a3 (p190) on a portion of the BCR-ABL1 sequence. Example of specific primers [6
] (green and blue) used to detect e1a2 with the quantitative RT-PCR method. Notice that the exon a2 sequence (blue) is lacking in the e1a3 transcript, represented by the dotted line. The lack of this primer binding site sequence results in a negative BCR-ABL1 p190 result with the p190 quantitative PCR test.