The extracellular domains, EC1 and EC2, of Dsg have been defined as the main target region recognised by autoantibodies from pemphigus patients (Amagai et al., 1992, 1995; Futei et al., 2000; Sekiguchi et al., 2001; Payne et al., 2005; Ishii et al., 2008; Chan et al., 2010; Di Zenzo et al., 2012), with some evidence of minor EC4 recognition, and IgG4 is now known to be the major pathogenic antibody isotype (Dmochowski et al., 1992; Allen et al., 1993; Wilson et al., 1993). Here, DSG1 is linked to pemphigus.