Cell–cell interactions are highly specific and are tightly regulated.  Genetic defects and dysregulation of these interactions can cause many different diseases.  Dysregulation that leads to leukocyte migration into healthy tissues can cause conditions such as acute respiratory distress syndrome and some types of arthritis. The autoimmune disease pemphigus vulgaris results from autoantibodies to desmoglein and other normal body proteins.  The autoantibodies disrupt the adhesion between epithelial cells.  This causes blisters of the skin and mucous membranes. Mutations in the connexin genes cause 8 human diseases including heart malformations and neurosensory deafness.