IFNB1 and myeloid sarcoma: MS patients under treatment with IFN-β or glatiramer acetate (no risk of systemic infections) or the ones under treatment with DMTs like dimethyl fumarate, fingolimod, siponimod, teriflunomide, natalizumab, ocrelizumab, and rituximab (low risk), might continue their treatment without specific concerns, unless they develop significant lymphopenia (<500 lymphocytes/μL for dimethyl fumarate and <200 lymphocytes/μL with fingolimod) [28,49,50,54,55].