IL6 and autoimmune encephalitis: IL‐6 is a cytokine thought to be a key player in B‐cell maturation and terminal differentiation into plasma cells, which secrete copious antibody.109 A study of neuromyelitis optica (NMO) with aquaporin‐4 antibody–positive patients identified IL‐6 as a key cytokine for B‐cell maturation and disease‐specific antibody production.110 Preliminary data using Tocilizumab, an anti‐IL‐6 monoclonal antibody, in NMO and autoimmune encephalitis is encouraging, and more work must be done to assess the efficacy of this as a standalone second‐line therapy.111