TEL/AML1 fusion resulting from a cryptic t(12;21) is the most common genetic lesion in pediatric ALL and defines a subgroup of patients with an excellent prognosis..     ///    "We now demonstrate that a TEL/AML1 chimeric transcript encoded by a cryptic t(12;21) is observed in 22% of pediatric ALL, making it the most common genetic lesion in these patients. "    ///    "Moreover, TEL/AML1 expression defined a distinct subgroup of patients characterized by an age between 1 and 10 years, B lineage immunophenotype, non-hyperdiploid DNA content and an excellent prognosis. "