COL17A1 and bullous pemphigoid: Although MMP clinical characteristics differ from those of bullous pemphigoid (BP) (younger patients, mucous membrane involvement, bullous cutaneous lesions predominantly on the head-and-neck, cicatricial evolution) (3), classical MMP, and BP share physiopathological features: both result from the activity of autoantibodies directed against hemidesmosomal proteins of basal keratinocytes, BP 230 (BP230) and BP 180 (BP180) antigens, predominantly the C-terminal region and BP180–NC16A epitopes in MMP and BP, respectively (2, 4, 5).