p73, a first p53 relative, has been identified at chromosome 1p36, a region that is deleted in variety of human cancers. This protein shares strong homology with p53 protein, suggesting functional similarities with p53. Indeed, p73 can activate p53 downstream genes inducing apoptosis or growth arrest in tumor cells lacking p53. This phenomenon leads us to investigate the function of p73 in ovarian cancer because aberrant p53 was very frequently found in this cancer. We hypothesize that DNA damaging agents trigger p53 dependent apoptotic pathway through p73 instead of p53 in ovarian cancer having aberrant p53. We selected SKOV3 ovarian cancer cell line having no p53 gene and treated this cell line with cisplatin. After the treatment, we examined the transcriptional level of p73 and p21. Moreover, to identify whether the status of p53 influence to the function of p73, we performed same experiment after inserting adenovirus mediated p53(Avp53) into cell line. We detected significantly increased transcripts of p73 whcn treated with cisplatin. But treated with Avp53 or combined treatment with cisplatin, the transcriptional levels were not changed. These data suggest that overexpression of p73 may be important to trigger apoptotic pathway when the p53 gene is lost, but not so important in cells having normal p53.