Radiation-inducible immediate-early gene IEX-1 is a protein that in humans is encoded by the IER3 gene. The protein is involved in cell proliferation and survival, including the protection of cells from TNF-induced apoptosis []. It is rapidly induced by growth factors, viral infections or chemical carcinogens [].IEX-1 has a dual role in extracellular signal-regulated kinase (ERK) signalling. Upon phosphorylation by ERK, IEX-1 acquires the ability to inhibit cell death induced by various stimuli. In turn, by binding to active ERK, IEX-1 potentiates ERK activation in response to various growth factors [, ].
