TNFSF13B and neuromyelitis optica: Although no differences were seen in serum BAFF levels among NMO patients, MS patients, and healthy donors, increased serum BAFF levels were found in MS patients treated with interferon‐β (Krumbholz et al., 2008; Vaknin‐Dembinsky et al., 2010) and NMO patients treated with rituximab (Gredler et al., 2013).