SNEA eosinophils significantly promoted the gene expression of Smad2, Smad3, Smad4, Smad5, Smad7, and Smad9 in ASMC, and Smad1, Smad2, Smad3, Smad4, and Smad7 in PF compared with control cells. Here, SMAD4 is linked to pemphigus foliaceus.