COL17A1 and mucous membrane pemphigoid: Cicatricial pemphigoid is a chronic autoimmune disease affecting the mucous membranes with the development of vesiculobullous lesions [12]. The antigen most commonly targeted is a hemidesmosomal protein of 180 kD known as bullous pemphigoid antigen 2 (BPAG-2), leading to the development of tense bullae that quickly progress to erosions, characteristically healing with scarring.