A novel p53-related gene, p73, was recently isolated and cytogenetically mapped to chromosome region 1p36. Functionally, p73 expression induces p21waf and suppresses tumor cell growth. We mapped p73 using radiation hybrids and localized the gene to an interval that putatively harbors a melanoma tumor suppressor locus. We then analyzed p73 transcripts from 24 melanoma cell lines using reverse transcription-PCR/single strand conformation polymorphism and identified nine polymorphic sequence changes (three novel and six previously published polymorphisms); furthermore, we found evidence of biallelic transcription in our cell lines. However, we did not detect any deleterious mutations. These data suggest that the p73 gene is unlikely to be essential in melanoma tumorigenesis.