Because keratins control intercellular adhesion (27) and their retraction is associated with signaling pathways in pemphigus (28), we speculate that PVIgG-induced keratin uncoupling from the desmosomal complex may contribute to the rapid mobilization and release of FasL, resulting in the upregulation of FasL in the intercellular milieu. Here, FASLG is linked to pemphigus.