The pineal gland (also called the pineal body, epiphysis cerebri, or epiphysis) is a small endocrine gland in the brain. It is shaped like a tiny pine cone, and is located near the center of the brain, between the two hemispheres, tucked in a groove where the two rounded thalamic bodies join. It produces a hormone that may weakly modulate wake/sleep patterns. A recent review of the pineal and its secreted hormone, melatonin, is available.