YAP1 and ovarian carcinoma: Yes-associated protein (YAP1) is known as a pivotal transcriptional co-activator of Hippo pathway, which participates in regulation of tumor pathogenesis, for example, kidney, ovarian cancers, and breast.[5,6] Further, YAP1 participates in many signaling pathways that regulate organic morphology, including ovary enlargement that is one of the major manifestations of PCOS.