TEL/AML1 was detected by RT-PCR and FISH analysis in both events.     ///    This observation confirms that TEL/AML1 alone is not sufficient to trigger ALL and that TEL deletion is a secondary event in leukemogenesis.     ///    Late ovarian relapse of TEL/AML1 positive ALL confirming that TEL deletion is a secondary event in leukemogenesis..     ///    "We demonstrated, using detection of IGH/TCR rearrangements and TEL/AML1 breakpoints sequencing that the cells were clonally related. "