RT-PCR analysis of NRG and RGN fusion transcripts in 3 t(4;11)(q21;p15) patients. P1, P2, and P3 are RT-PCR products from peripheral blood mononuclear cells from the patients. C1 and C2 are RT-PCR products from peripheral blood mononuclear cells of normal donors. Samples marked with a minus sign are negative control RT-PCRs without reverse transcriptase. H₂O controls are negative control RT-PCRs without target. The lane marked m contains both SPP1/EcoRI and pUC19/Hpa II molecular weight markers. The most prominent bands in the RGN PCR of patient no. 3 are alternative splicings of RGN with and without exon B.