Giancarlo Comi, MD, Vita-Salute San Raffaele University, Milan, Italy, describes the mechanism of action of ozanimod, a recently approved drug for the treatment of relapsing-remitting multiple sclerosis (MS), highlighting its benefits over fingolimod. Both ozanimod and fingolimod are sphingosine 1-phosphate (S1P) receptor modulators. However, whilst fingolimod targets four out of five S1P receptors, ozanimod targets only S1P1 and S1P5, thereby causing less adverse effects. Prof. Comi explains that through its action on S1P1, ozanimod prevents aggressive lymphocytes from entering the circulation and the brain, thus preventing brain damage. Due to its decreased toxicity, it is not necessary to monitor patients in the hospital during the first day of treatment. Finally, Prof. Comi comments on other novel S1P receptor modulators, that could enable selection of the most appropriate drug for each patient. This interview took place during the XXV World Congress of Neurology.