Autoreactivity against plakophilin-3 (PKP3) has been demonstrated by Lambert et al. in five PNP/PAMS (100%) sera and in one PV (25%) serum in a series that evaluated sera from five PNP, four PV, two PF, five bullous pemphigoid (BP), one cicatricial pemphigoid, and one linear IgA dermatosis (53). Here, PKP3 is linked to mucous membrane pemphigoid.