Migraine is a frequent, disabling condition, of great social and economical impact worldwide. This condition is more frequent in women and subjects with autoimmune and/or inflammatory diseases. Cytokine and immune cell dysregulations have been evidenced in migraine. Inflammation seems to play an important role in migraine chronification; however, the inflammatory mechanisms involved in migraine pathophysiology remain unclear. Regulatory T (Treg) cells play a central role in maintaining immune homeostasis. They regulate effector T (Teff) cell proliferation and cytokine production, through several suppressive mechanisms, such as the hydrolysis of adenosine triphosphate (ATP) into adenosine (ADO), mediated by surface enzymes Cluster Differentiation 39 (CD39) and Cluster Differentiation 73 (CD73). ATP is involved in pain processes in migraine, and insufficient hydrolysis could participate in pain chronification. Recent studies suggest altered proportions of Treg cells in migraine, and decreased levels of CD39-positive (CD39+) Treg cells, suggesting Treg suppressive functions may be decreased in the disease. However, there have been no functional studies to date to confirm this hypothesis. The investigators believe Treg suppressive functions may be decreased in migraine, and that such alterations may be caused by a malfunction in the ADO pathway.