A 2-kb 5' fragment of hPTN (human pleiotrophin-encoding) genomic DNA was sequenced. Within this region we identified a new, upstream exon (U2). Cloning and sequencing of the PCR products of cDNAs from a human melanoma cell line revealed that a 401-bp intron was spliced out between exon U2 and a previously described untranslated exon U1. Our analysis also revealed that previously reported transcription start points (tsp) of PTN are located within exon U1.