Tre is a recombinant gene isolated from NIH3T3 cells transfected with human Ewing's sarcoma DNA. It is composed of three major genetic elements derived, 5' to 3', from human chromosomes 5, 18 and 17. We report here on transcripts from the 3' domain of tre. The transcripts were cloned from a cDNA library of cytoplasmic poly(A)+ RNA from tre-transfected NIH3T3 tumor cells. The complete cDNA sequence, 8201 nucleotides, possessed an unusually long non-coding region and a translatable region with two open reading frames. In one cDNA clone, the presence of two insertions suggested the possibility of alternative splicing. The sequence mapped to the centromere-proximal region of 17q. Transfection-tumorigenicity assays with the open reading frames subcloned into expression vectors were positive for the reading frame adjacent to the 5' non-coding region and negative for the second, downstream, reading frame and the possible alternatively spliced versions of both reading frames. Analysis of the 786 amino acid sequence deduced from the 5' reading frame predicted a highly hydrophilic protein with two charge clusters suggesting nucleic acid-binding properties. When used as probe, the cloned sequence detected RNA transcripts in a wide variety of human cancer cells regardless of their lineage of origin from different tissues, but not in human cells from normal tissue.