Integrin beta-6 is a protein that in humans is encoded by the ITGB6 gene. It is the β6 subunit of the integrin αvβ6. Integrins are αβ heterodimeric glycoproteins which span the cell’s membrane, integrating the outside and inside of the cell. Integrins bind to specific extracellular proteins in the extracellular matrix or on other cells and subsequently transduce signals intracellularly to affect cell behaviour. One α and one β subunit associate non-covalently to form 24 unique integrins found in mammals. While some β integrin subunits partner with multiple α subunits, β6 associates exclusively with the αv subunit. Thus, the function of ITGB6 is entirely associated with the integrin αvβ6. The dimer αvβ6-integrin is expressed by epithelial cells and frequently found in high density on the surface of carcinomas (synonymous to cancers of epithelial origin). This enables targeting of these cancers with pharmaceuticals and functional imaging agents, such as cancer cell specific positron emission tomography (PET) imaging using the αvβ6-integrin targeted radiotracer 68Ga-Trivehexin.
