Once a tumour phenotype was established, a multiplex gene expression assay was used to determine a genetic link between the identified precursor lesion of the sex cords in ovaries of 3-month Fancd2−/− mice and the tubulostromal adenoma ovarian tumour phenotype in 1-year old Fancd2−/− mice. The gene discussed is FANCD2; the disease is ovarian neoplasm.