 We prospectively examined the frequency of the t(12;21)TEL-AML1 fusion in 504 children with newly diagnosed standard risk ALL using RT-PCR assays.     ///    This prospective study significantly expands the knowledge gained from previous studies regarding the prognostic significance of t(12;21)TEL-AML1 fusion in pediatric ALL..     ///    Expression of TEL-AML1 fusion transcripts and response to induction therapy in standard risk acute lymphoblastic leukemia.. 