Roles of transforming growth factor-α in mammary development and disease

Transforming growth factor-alpha (TGF alpha) is a member of the epidermal growth factor (EGF) family. Expression of TGFa is highly regulated in response to exogenous cellular signals including cytokines and other growth factors. The growth factor has been found to be indispensable for proper development of many tissues and organs. TGFa has also been implicated in numerous disease states including forms of breast cancer. This minireview summarizes the basic biology of TGFa and its actions during normal and pathogenic development of the mammary epithelium.