Pemphigus vulgaris (PV) is a life-threatening autoimmune disease affecting the skin, causing painful erosions on the skin and mucous membranes. PV is caused by IgG4 autoantibodies that target desmoglein 1 (DSG1) and DSG3, which are involved in keratinocyte cell-cell adhesion. There is a high unmet medical need for PV, since current therapies rely on systemic corticosteroids and immunosuppressants.