What is the thymus gland? Learn about the gland that trains T cells to fight infections and diseases, including cancer. Read More What is the pineal gland? Everything you need to know about the tiny gland that governs your sleep/wake cycle. Read More What are hormones and how do they work? Learn more about hormones and the system that controls them. Read More Three expert ways to balance your hormones Learn how to use rest, good food, and exercise to keep your hormones balanced and healthy. Read More 1 2