The cross-talk between heterologous signalling systems of the cell represen
ts a new dimension of complexity in the molecular communication network tha
t governs a great variety of physiological processes. In pathophysiological
ly transformed cells, key elements of this network could offer unique oppor
tunities for pharmacological intervention. In this article, the current sta
te of knowledge regarding the role of epidermal growth factor (EGF) in such
a network is described and the recent advances made in the elucidation of
the mechanism underlying EGF receptor transactivation are discussed.