CYP24A1 and myeloid sarcoma: In this study, we compared the expression levels of vitamin D receptor (VDR) and of its responsive gene CYP24A1 (i.e., the gene encoding the catabolic enzyme inactivating 1,25(OH)2D3) as well as the secretory activity of IFN-DC and IL4-DC obtained from healthy donors and MS patients, either free of therapy or undergoing IFNβ therapy.