Rock et al. reported that IgG4 was the most common (100 %) of anti-desmoglein (Dsg)-1 antibodies detected in sera of patients with pemphigus foliaceus, and showed the pathogenicity of IgG4-type anti-Dsg-1 antibody using Balb/c mice [18]. This evidence concerns the gene DSG1 and pemphigus foliaceus.