By studying the embryology of the skin, one can gain insight into the mechanisms of certain genetic disorders. For example, one of the more studied groups of genetic diseases are the congenital blistering diseases. The various types of epidermolysis bullosa are all caused by genetic defects in proteins responsible for adhesion of keratinocytes. A firm understanding of the embryology of skin development is essential for understanding the pathogenesis of these diseases and ultimately for developing a mechanism to detect and therapeutically treat them.