 TEL (ETV6)-AML1 (RUNX1) chimeric gene fusions are frequent genetic abnormalities in childhood acute lymphoblastic leukemia (ALL).     ///    "In all of the cases evaluated, the clonal relatedness of diagnostic and relapse cells was confirmed by the retention of clonotypic TEL-AML1 genomic sequence and/or at least one identical immunoreceptor gene rearrangement. "    ///    "Moreover, we compared the relatedness of diagnostic and relapse clones using immunoglobulin and T-cell receptor genes rearrangements and clonotypic TEL-AML1 genomic fusion. "    ///    These data provide further evidence that TEL deletions are secondary to TEL-AML1 fusions in ALL. 