GJA4 and polycystic ovary syndrome: The results demonstrated that the expression of cleaved-caspase-3, the marker for follicle atresia, in the ovarian granulosa cells was significantly increased in PCOS mice compared with the control mice; however, the expression of GDF-9 in oocyte, a positive regulator of follicle development, and the expression of the bridge protein CX37/GJA4 in granulosa cells, which mediates the connection and communication between oocyte and granulosa cells, were significantly reduced in PCOS ovaries compared with the control.