Integrins are transmembrane receptor glycoproteins that play an important role in facilitating cell-cell and cell-matrix adhesion. The integrins, are structurally heterodimers, made up of different combinations of alpha and beta subunits. The ITGB4 gene codes for the Integrin Beta 4 Subunit protein. Along with an integrin alpha subunit, it forms the alpha6beta4 integrin, which is an important constituent of the epidermis. This protein plays an important role in strengthening and stabilizing the skin, in particular in holding the layers of the skin together. Not surprisingly therefore, mutations in the ITGB4 gene have been found to result in junctional epidermolysis bullosa with pyloric atresia (JEB-PA), in which patients present with a skin blistering and a life-threatening obstruction of the digestive tract.
Integrins also play a major role in the migration of cancer cells and their resistance to apoptosis. Mutations in ITGB4 are therefore, also implicated in the birth and progression of epithelial carcinomas.