Book excerpt: This is the most comprehensive, up-to-date reference on this post-translational modification of proteins, which is intimately linked with DNA repair, maintenance of genomic stability, transcriptional regulation, cell death and a variety of other cellular phenomena as well as with a variety of pathophysiological conditions, including ischemia-reperfusion damage, Parkinson’s disease, Type I diabetes mellitus, hemorrhagic and septic shock and other inflammatory conditions. Richly illustrated, it offers 19 chapters written by international experts.