The importance of collagen XVII for the integrity of the dermoepidermal junction is demonstrated in inherited skin diseases caused by mutations in the COL17A1 gene, including junctional epidermolysis bullosa (JEB), and in numerous subepidermal blistering skin disorders with autoantibodies to collagen XVII (BP180), such as bullous pemphigoid (BP), linear IgA bullous dermatosis, lichen planus pemphigoides, and pemphigoid gestationis [Figure 1; (19, 20)]. This evidence concerns the gene COL17A1 and bullous pemphigoid.