GJC2 and myeloid sarcoma: In human demyelinating disorders, we and others have reported the extensive loss of glial Cx43, Cx32, and Cx47 in active demyelinating lesions in cases of multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and Baló's concentric sclerosis, an extremely rare fulminant demyelinating disease [12, 13, 14].