Th17 cells are also present in lesional skin (Arakawa et al., 2009): accordingly, a comparison of the expression profiles of lesional versus perilesional and healthy skin from a patient with pemphigus identified an IL-17A-dominated immune signature, with high expression of genes involved in the IL-17A signalling pathway (Holstein et al., 2021). This evidence concerns the gene IL17A and pemphigus.