TRANSFORMING GROWTH-FACTOR-ALPHA

Transforming growth factor alpha (TGF alpha) is a close relative of ep idermal growth factor (EGF), the first polypeptide mitogen discovered in 1962 (Cohen, 1962). TGF alpha, like EGF, exerts its effect on cells through binding to the EGF-Receptor (EGF-R). Here we review the molec ular and cell biology of TGF alpha before proceeding to describe our o wn work an signaling molecules induced in response to activation of th e EGF-R.