Only one out of a thousand B cells carries TEL-AML1 fusion gene.     ///    "Practically this means that among a hundred children born with TEL-AML1 fusion gene, only one child will later in its life develop ALL. "    ///    TEL-AML1(+) body cell count is low because TEL-AML1 fusion is generated at cell level of 10(-3) to 10(-4) just during the late fetal lymphopoiesis i.e.     ///    The bottleneck is caused by the very low body TEL-AML1(+) cell count.     ///    It was the level of TEL-AML1(+) cells? frequency.     ///    For childhood TEL-AML1(+) acute lymphoblastic leukemia (ALL) this equates to approximately 100 times.     ///    Childhood leukemia genetic bottleneck phenomenon related to TEL-AML1: the postulation by a mathematical model.. 