PGR and neoplasm: We also observed statistically significant differences between the two molecular subtypes of HGSOC in terms of tumor size, where a smaller tumor volume was characteristic of progesterone receptor-negative HGSOC, with increased levels of extracellular miR-16-5p, miR-17-5p, miR-93-5p and miR-20a-5p, and with more aggressive tumor behavior responsible for the failure of optimal surgical resection in most cases.