IGHG3 and chronic inflammatory demyelinating polyradiculoneuropathy: Ig is progressively produced by maturing B cells in a sequential order (IgM→IgG3→IgG1→IgG2→IgG4) (Collins and Jackson, 2013), which is in accordance with the fact that both the positive rate and titer of IgG4 are predominant in CIDP, but IgM and IgG3 are more detectable in Guillain-Barré Syndrome (GBS) (Burnor et al., 2018).