It is important to determine whether exposure to cosmic radiation induces disease or toxicity in astronauts and space travellers[1].In this investigation,we used a comparative proteomics approach based on a 2-DE reference map to detect alterations in protein expression in the serum of Swiss–Webster mice following exposure to iron ion radiation(IIR),and to identify biomarkers of liver toxicity.The results reveal the underlying molecular mechanisms of liver disease or toxicity following exposure to IIR.