Bullous pemphigoid (BP) is one of the most common autoimmune bullous diseases and is associated with tissue-bound and circulating autoantibodies directed against BP antigen 180 (BP180, BPAG2, or type XVII collagen) and BP antigen 230 (BP230 or BPAG1e—epithelial isoform) (1). The gene discussed is COL17A1; the disease is bullous pemphigoid.