IFNB1 and myeloid sarcoma: In relapsing–remitting (RR)-MS–the most common disease subtype—and clinically isolated syndrome, dysfunction of CD3−CD16+CD56dim (CD56dim) and CD3−CD16−CD56bright (CD56bright) NK cell subsets was shown to be associated with disease progression; specifically, the size of the latter cell population was significantly increased in IFN-β-treated RR-MS patients compared to untreated patients and healthy subjects (165).