Transforming growth factor alpha.

ABSTRACT Transforming growth factor alpha (TGFα) is a close relative of epidermal growth factor (EGF), the first polypeptide mitogen discovered in 1962 (Cohen, 1962). TGFα, like EGF, exerts its effect on cells through binding to the EGF‐Receptor (EGF‐R). Here we review the molecular and cell biology of TGFα before proceeding to describe our own work on signaling molecules induced in response to activation of the EGF‐R.