BH3-interacting domain death agonist (BID) is the most significant differentiating gene between the two groups as found in the nCounter analysis (NMO: 131.4 ± 9.3 nCounts, HCs: 73.7 ± 8.0 nCounts, p < 0.0001, Figure 2a). This evidence concerns the gene BID and neuromyelitis optica.