Additionally, autoantibodies associated with central nervous system demyelination (AQP4, MOG, MBP), encephalomyelitis/encephalitis (IgLON5, DPPX, DRD2, mGluR5, mGluR1, neurexin-3α, NMDA, AMPA1, AMPA2, LGI1, GABAb, CASPR2), and gangliosides (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GQ1b, GT1a, GT1b, sulfatide) were undetectable in both blood and CSF, even on two separate occasions. Here, IGLON5 is linked to viral encephalitis.