The trigemino-vascular system (TVS) plays a key role in migraine pathophysiology. Glial cells are abundant in the TVS system and mainly in the trigeminal ganglion. S100B protein is a calcium-binding protein, found in the cytoplasm of glial cells in the central nervous system, which is released in response to inflammatory stimuli. Previous works analyzing S100B in migraineurs have offered contradictory results.