Although all of the prognostic markers above chosen for testing have been well studied in ovarian cancer (in some cases with mixed results), only BRCA2, SNAI2 and CXCL12 were a particularly convincing marker of outcome in OvMark. We then queried all human genes in OvMark so as to identify which genes had the greatest association with OS of ovarian cancer patients. This evidence concerns the gene CXCL12 and ovarian cancer.