Of note, IL-21 single positive CD4+ T cells tended to be increased in pemphigus (Fig 5D) and could be found more frequently (median: 2.36% CD4+ T cells) compared to IL-17/IL-21 double positive CD4+ T cells (median: 0.11% CD4+ T cells) in pemphigus patients. This evidence concerns the gene CD4 and pemphigus.