And FSH as well as LH are both stimulated by the gonadotropin releasing hormone released by the hypothalamus. So estrogen is basically released by two structures. So estrogen is initially released by our ovarian follicle, this structure here. Now, once our ovulation process actually takes place and we form the corpus luteum, then the corpus Lewdium begins to release our estrogen. So we have two structures inside our ovary that are capable of releasing our estrogen hormone. So estrogen is released by the ovarian follicle, which is the basic unit of the structure inside the ovary.