 In contrast to the EWS/FLI1 fusion which is represented by a t(11;22)(q24;q12), EWS/ERG fusions are frequently cytogenetically not detectable.     ///    EWS/ERG transcripts were detected by RT-PCR in all cases.     ///    Fine-mapping of cytogenetically undetectable EWS/ERG fusions on DNA fibers of Ewing tumors..     ///    This finding suggests that EWS/ERG fusions in ETs may be generated by an inversion of the ERG gene or a part thereof followed by an insertion into the EWS gene on the der(22).     ///    "In contrast, co-hybridization of probe PT1526 containing the ERG breakpoint region with G9 revealed the juxtaposition of two signals per interphase nucleus in all three cases indicating the EWS/ERG fusions. "