The efficacy of 1,25(OH)2D3 in generating Th2 cells and in alleviating EAE requires the STAT6 transcription factor that lies upstream of GATA-3, raising the possibility that other approaches to stimulate STAT6 may increase the effectiveness of vitamin D. Thus, our results of the mechanistic understanding of vitamin D activity have relevance to the improvement of therapeutics to ameliorate MS. The gene discussed is STAT6; the disease is myeloid sarcoma.