In actively demyelinating lesions, 26 of 35 (74.3%) lesions were classified as pattern A or B, while 18 of 41 (43.9%) chronic active lesions were classed as pattern A or B. None of the 13 chronic inactive lesions was classed as pattern A or B. Cx30 expression levels were very low in astrocytes in NMO/NMOSD lesions, similar to that in the white matter of normal controls (data not shown). Here, GJB6 is linked to neuromyelitis optica.