For the first time, researchers have shown how Mullerian inhibiting substance (MIS), also known as anti-Mullerian hormone, a key reproductive hormone, suppresses follicle development and prevents ovulation in females. “Understanding the mechanism of follicle development by MIS opens the door to creating novel approaches to contraception, preserving the eggs of young girls undergoing chemotherapy, enhancing the success of fertility treatment, and potentially delaying menopause,” says David Pépin, Ph.D., an associate molecular biologist in the Department of Surgery at Massachusetts General Hospital (MGH) and senior author of new research published in the Proceedings of the National Academy of Sciences (PNAS).