Integrin beta-6 is a protein that in humans is encoded by the ITGB6 gene. It is the β6 subunit of the integrin αvβ6. The principal function of αvβ6 is the activation of cytokine transforming growth factor-b1 (TGF-β1). Integrin αvβ6 is found exclusively on epithelial cells. In most resting normal cells, little ITGB6 is produced, however the highest levels are found in the stomach, gall bladder and lung. ITGB6 levels increase in cells remodelling tissues so αvβ6 expression is increased in development, wound healing, but also in fibrosis and cancer. While αvβ6 promotes normal functions such as wound repair, excess αvβ6 production promotes diseases such fibrosis and cancer. High αvβ6 expression in fibrosis and cancer is usually associated with a poorer prognosis. Increased αvβ6 expression occurs in up to one third of solid tumours including breast cancer, lung cancer and pancreatic cancer. Because it is not found on most normal cells, it is a potential therapeutic and imaging target in cancer research. αvβ6 is a potential drug target in treating fibrosis.