More than 3 times more women than men have multiple sclerosis (MS). Over the past 50 years, this ratio has been steadily increasing.1,2 The burdens to those who battle this disease, as well as the costs for society in dealing with MS, are substantial, and deciphering this 50-year-old trend in female preponderance in this disease is critical.1,2 In attempting to understand this growing imbalance, a number of intriguing discoveries have been made. These discoveries illuminate the pathogenesis of MS, with applications and benefits for both men and women. These breakthroughs potentially allow for the repurposing of certain approved drugs for potential use as treatments of MS.