At year 2, the proportion of alemtuzumab-treated RR-MS patients who were free from new or enlarging T2 lesions ranged from 52% to 54% (vs 32 - 42% of IFN treated patients), being 91 to 93% of the patients free from gadolinium-enhancing lesions (vs 77 - 81% of IFN treated patients). Here, IFNA1 is linked to myeloid sarcoma.