GFAP and myeloid sarcoma: Three MS cases (MS-3, 4, and 6) showed Cx43, AQP4, and MLC1 loss in GFAP-positive astrocytes in active lesions beyond the areas of demyelination as determined by myelin protein staining, whereas the remaining three MS cases (MS-1, 2, and 5) showed preservation of astrocytic proteins including Cx43, AQP4, MLC1 and GFAP in actively demyelinating lesions (Table 6).