ITGB4 and junctional epidermolysis bullosa: Although most cases of JEB are caused by pathogenic variants occurring in the genes encoding for classical components of the lamina lucida, such as laminin 332 (<i>LAMA3</i>, <i>LAMB3</i>, <i>LAMC2</i>), integrin α6β4 (<i>ITGA6</i>, <i>ITGB4</i>), and collagen XVII (<i>COL17A1</i>), other variants have also been described.