In three cytogenetically negative cases, RT-PCR detected cryptic CBF rearrangements (one AML1-ETO and two CBFB-MYH11).     ///    " Our objective was to establish a multiplexed assay using the Biomed 1 primers to detect AML1-ETO transcripts and 10 different CBFB-MYH11 transcripts, using BCR and ABL transcripts as controls. "