Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Premature Ovarian Failure ?
    ### Response:
    Premature ovarian failure (POF) is when a woman's ovaries stop working before she is 40.    POF is different from premature menopause. With premature menopause, your periods stop before age 40. You can no longer get pregnant. The cause can be natural or it can be a disease, surgery, chemotherapy, or radiation.
    