Since the emergence of life on Earth, biological systems have relied on redox reactions to fuel metabolism and growth. At the heart of redox biology are the oxidative modifications of the thiol (-SH)-side chain of cysteines residues in proteins that serve catalytic functions in many enzymes, help in the folding and trafficking of proteins, and act as reversible protein molecular switches to modulate function and regulate cell signaling. This Gordon conference focuses specifically on the redox modification of cysteine and also methionine residues, on small-molecule and protein agents that modulate these redox modifications, and on the cellular processes that are dependent upon these redox modifications. These include protein oxidative folding and secretion, mitochondrial functions, oxygen, ROS and RNS sensing and signaling, ROS and RNS metabolism, DNA synthesis and gene expression. Discussion topics will encompass the chemistry of cysteine, methionine and ROS/RNS species, the biochemistry and cell biology of thiol-based redox processes, and the development of novel tools to study thiol-based processes. Because aging leads to progressive breakdown of redox homeostasis, a special focus will be made on the biological causes and molecular basis of aging and associated diseases (i.e. inflammation, cardiovascular and aggregation diseases) that are redox-regulated. This interdisciplinary conference is in its fifth cycle after four very successful meetings in the U.S. (2006 and 2012) and Italy (2008 and 2010). By bringing together investigators with varied expertise in biophysical methods, bioinformatics and animal and cellular model systems, with clinical researchers and physicians focused on disease processes, the meeting is expected to further stimulate collaborations and catalyze scientific progress as has been exemplified by the successes of the previous meetings. For the second time, the GRC will be preceded by a Gordon Research Seminar (GRS) (July 19-20, 2014), which will provide an opportunity for graduate students and postdoctoral scientists to formally present research and engage in scientific discussions.