WNK2 and polycystic ovary syndrome: By way of example, RNA-sequencing (RNA-Seq) and microarray-based comparison of ovarian tissue from PCOS women with the controls revealed that Wnt (Wingless-related integration site) signaling pathway, insulin receptor signaling pathway, MAPK (Mitogen-Activated Protein Kinase) signaling pathway, aberrant status of mitochondrial energy metabolism, TNF (Tumor Necrosis Factor) signaling pathway, regulation of cell cycle and apoptosis are likely to be involved in the PCOS development2–5.