ENPP2 and relapsing-remitting multiple sclerosis: The sphingsosine 1-phosphate (S1P) receptor antagonist fingolimod, which is one of the most effective relapse preventing drugs in relapsing remitting multiple sclerosis (RRMS) [10], has been reported to also be a slow acting autotaxin inhibitor [57] and protects against deregulation of signaling lipids at the blood brain barrier [61].