The volume includes contributions by some of the leading scientists in the field of thiol oxidation/reduction (redox) biochemistry, focused on the biological/pathophysiological implications of newly discovered functions of cellular thiols, such as glutathione in the first place. Recent research has shown that thiols - besides their well established role in cell defense against prooxidant damage - can mediate physiological functions of free radicals and other prooxidants, e.g. in modulation of protein synthesis and folding, signal transduction, cell proliferation. The volume is timely addressing many of these novel and intriguing insights, adding elements for a better understanding of the role of redox processes in important human pathologies, such as atherosclerosis, ischemiareperfusion, cancer and Alzheimer's disease.