In addition, analysis of the CD8+ TCR repertoire in alemtuzumab-treated patients with relapsing-remitting multiple sclerosis (RRMS) who develop a secondary autoimmune disease (vitiligo) revealed greatly increased clonality and reduced repertoire diversity in those patients compared to treatment-naive patients with RRMS (21). This evidence concerns the gene CD8A and relapsing-remitting multiple sclerosis.