Coffler et al. [12] suggest that in PCOS patients, follicular granulosa cells can show two types of response to FSH: (1) PCOS patients show remarkably higher E2 levels in response to FSH above the threshold dose; (2) PCOS patients treated with a single FSH stimulation exhibit much faster rise and decay of the E2 levels, which were much different from the response of the control patients. Here, BRD2 is linked to polycystic ovary syndrome.