BRD2 and Hyperinsulinemia: Hyperinsulinemia and/or high levels of LH synergistically improve the sensitivity of granulosa cells to LH, leading to premature differentiation of granulosa cells and an imbalance in LH/FSH levels, so that FSH deficiency destroys the choice of dominant follicles, leading to the accumulation of small antral follicles (68, 69); at the same time, the premature response of small antral follicles to high LH promotes the early terminal differentiation of follicles (70).