Since miR-509-3p's strongest anti-correlated predicted targets in TCGA ovarian tumors were enriched for components of the extracellular matrix (ECM), and effects on ECM components are consistent with effects on 3D spheroid formation, we propose that miR-509-3p may act in ovarian cancers by targeting both ECM components and YAP1. We anticipate that the miR-509-3p/YAP1/ECM axis offers a novel therapeutic focus for controlling metastatic progression in HGSOC. The gene discussed is YAP1; the disease is ovarian carcinoma.