 The chromosomal translocation t(12;21) (p12;q22) which results in the TEL-AML1 fusion gene is the most frequent genetic rearrangement in childhood B-lineage acute lymphoblastic leukemia (ALL).     ///    "Furthermore, we could detect the TEL-AML1 transcript in the peripheral blood of t(12;21)-positive patients and we used this to assess minimal residual disease (MRD) in patients during chemotherapy. "    ///    The TEL-AML1 fusion transcript was detected in nine of fourteen patients.     ///    Molecular detection of TEL-AML1 transcripts as a diagnostic tool and for monitoring of minimal residual disease in B-lineage childhood acute lymphoblastic leukemia.. 