The desmosomal cadherins desmoglein (DSG) 3 and DSG1 are targets of autoantibodies in the potentially fatal blistering disease, pemphigus vulgaris (PV)(Stanley and Amagai, 2006). DSGs are synthesized as preproproteins, which are processed first in the endoplasmic reticulum to remove the signal sequence and subsequently by the Golgi proprotein convertases to remove the propeptide before transport to the cell surface. The cadherin propeptide is thought to modulate the conformation of the extracellular domains to prevent intracellular aggregation because of interaction with other cadherins within the secretory pathway. Propeptide cleavage occurs upstream of the conserved tryptophan residue at position 2, which is responsible for cadherin strand dimer formation, suggesting that propeptide removal may unmask residues important in intermolecular adhesion. The proprotein convertase furin processes recombinant DSGs in baculoviral overexpression systems (Posthaus et al., 2003), which are widely used for pemphigus research and clinical diagnostic purposes. Commercial DSG ELISA kits use baculovirally produced recombinant DSG antigen (Ag) and have been shown to be a sensitive and specific diagnostic tool for pemphigus