HEY2 and polycystic ovary syndrome: Immunoreactivity of Notch2, Hey2, and Hes1 was significantly higher in granulosa cells of antral follicles from PCOS patients than in those from control patients (p < 0.05 for Notch2 and Hey2, and p < 0.01 for Hes1) (Figure 1B–J).