CLN5 and myeloid sarcoma: The authors concluded that upregulation of CLN-5 by leukocytes in MS reflects interaction of these cells with “additional cell types.” That expression of CLN-5 by PBLs from MS patients was diminished following successful anti-inflammatory therapy is also consistent with the argument that acquisition of CLN-5 by leukocytes is not merely a result of leukocyte extravasation but, rather, occurs prior to it—while the cells are still in the blood.