LGI1 and viral encephalitis: The major findings of our research include: first, a heavy chain common clone of B cell receptor appeared in 11 of 12 patients, but not in healthy people or patients with anti-LGI1 encephalitis, MS, or NMOSD; second, four shared clonotypes presented among different patients with anti-NMDAR encephalitis; third, the V-D-J gene family usage preference of patients with anti-NMDAR encephalitis were different from healthy people, although they have similar antibody mutation rate.