S1PR1 and infection: Certain DMTs are known to be associated with increased risk of other infections: anti-CD20 drugs such as rituximab, ocrelizumab, and ofatumumab are associated with a range of serious infections, including respiratory tract infections (9, 10); sphingosine-1-phosphate receptor (S1PR) modulators, including fingolimod, ozanimod, and siponimod, which sequester lymphocytes in lymph nodes, are associated with increased risk of herpesvirus infections or reactivations (11); and natalizumab, an anti–α-4 integrin mAb, with a risk of progressive multifocal leukoencephalopathy (9).