Tumors may form in the pituitary gland, an organ in the brain that controls the release of hormones in the body. Hormones are chemical messengers that send signals to the body's organs to keep them working properly. Pituitary tumors have various effects on hormones and health, and they can cause many different health complications in adults and children. These tumors can develop on their own or be caused by one of many inherited disorders. NICHD scientists are exploring the causes of pituitary tumors and their related disorders and seeking better ways to diagnose and treat them.