Alopecia areata (AA) is a recurrent autoimmune type of hair loss that affects about 5.3 million people in the United States alone. Despite being the most prevalent autoimmune disease, the molecular and cellular mechanisms underlying this complex disease are still poorly understood, and rational treatments are lacking. Further efforts are necessary to clearly pinpoint the causes and molecular pathways leading to this disease and to find evidence-based treatments for AA. The authors focus on the central role of genetics for gaining insight into disease pathogenesis and setting the stage for the rational development of novel effective therapeutic approaches.