If our observation is confirmed in other, ideally larger cohorts, if a clinical relevance becomes evident and if more neuropathological evidence supports the complement-hypothesis, the use of complement-inhibiting compounds (like eculizumab, ravulizumab, and zilucoplan, licensed for myasthenia gravis [8]) could become a specific therapeutic option for patients with anti-LGI1-IgG subclasses 1/2/3. The gene discussed is LGI1; the disease is myasthenia gravis.