IgG4 pathogenicity could be demonstrated by passive transfer to experimental animals in (1) MuSK MG (MuSK-IgG4), (2) PV (desmoglein 3-IgG4), (3) pemphigus foliaceus (PF, desmoglein 1 and/or 3-IgG4), (4) chronic inflammatory demyelinating polyneuropathy (CIDP, contactin-1-IgG4), (5) CIDP (neurofascin 155-IgG4), and (6) TTP (ADAMTS13-IgG4)13. This evidence concerns the gene DSG3 and chronic inflammatory demyelinating polyradiculoneuropathy.