CD4 and myeloid sarcoma: This is indicated by the ability to adoptively transfer disease and via T‐cell inhibition.2, 3, 4 In many cases disease is mediated by CD4 T cells,3 although pathogenic CD8 T‐cell models have been developed to mirror the CD8 predominance in some MS lesions.5 However, supportive data for a CD4, T helper type 17‐mediated pathogenesis in MS is largely circumstantial and not supported by the perceived failure of CD4‐depleting monoclonal antibodies (mAb).6, 7, 8