We therefore investigated STIC, a precursor lesion of the FT that is recognized to be the source of most ovarian HGSC.22–24 As part of routine clinical assessment of 6 ovarian cancer patients, longitudinal sections of FFPE FT tissue samples were stained with H&E to identify STIC regions, which were subsequently confirmed by IHC to show overexpression of p5339 and increased nuclear levels of Ki-67 (a standard marker of cell proliferation)40 (Fig. 5A). This evidence concerns the gene MKI67 and ovarian carcinoma.