Previous data had indicated that FcRn is involved in the pathogenesis of autoantibody‐mediated diseases: First, genetic alterations of the Fc‐molecule that alter its binding to FcRn, have been shown to be associated with autoantibody‐mediated disease—specifically in pemphigus, where the p.Arg435his variation of IgG3 that has a high affinity to the FcRn is associated with disease susceptibility (Recke et al., 2018). Here, IGHG3 is linked to pemphigus.