GADD153 (Growth arrest and DNA damage-inducible 153; DNA-damage inducible transcript 3;) is a small nuclear protein that is capable of dimerizing with transcription factors C/EBP alpha and beta. Once dimerized, this complex inhibits the normal binding and function of C/EBP to classical binding sites. Inversely, the C/EBP GADD153 dimer gains binding activity to other non classical C/EBP stress related targets. Under normal cellular conditions this protein is not expressed in detectable levels, but is highly unregulated during times of cellular/ER stress. Examples of GADD153 inducing stress include: treatment with tunicamycin, nutrient starvation and reducing agents that interfere with the calcium flux across the ER membrane.