EGF mediates multiple signals: dependence on the conditions.

Epidermal growth factor (EGF) has been reported to both increase and decrease proliferation and apoptosis. In KB cells, EGF-induced alteration in proliferation and apoptosis are concentration and time dependent. High concentrations of EGF (10(-7) and 10(-8) M) stimulated proliferation and inhibited apoptosis at 24 h, with apoptosis increasing with prolonged exposure.