Ovarian cancer has the highest mortality rate of the gynaecological cancers. This is partly due to the lack of effective screening markers. In this study, oligonucleotide microarrays complementary to -12,000 genes were used to establish a gene expression microarray (GEM) profile for normal ovarian tissue, as compared to stage III ovarian serous adenocarcinoma and omental metastases from the same individuals. The GEM profiles of the primary and secondary tumours from the same individuals were essentially alike, reflecting the fact that these tumours had already metastasised and acquired the metastatic phenotype. A novel biomarker, mammaglobin-2 (MGB2), was identified which is highly expressed specific to ovarian cancer. MGB2, in combination with other putative markers identified here, could have potential for screening.