Nevertheless, because inhibition of EGFR strongly reduced loss of cell adhesion in response to PV-IgG but not PF-IgG and Ca2+ chelation significantly reduced effects of both PV-IgG and PF-IgG, we conclude that both Dsg3- and Dsg1-dependent signaling mechanisms contribute to loss of keratinocyte adhesion in pemphigus. The gene discussed is EGFR; the disease is pemphigus.