Cytokines are protein messengers responsible for cellular communication with great therapeutic potential to control inflammatory and immune disorders such us cancer, rheumatoid arthritis, multiple sclerosis and inflammatory bowel disease. Despite the solid scientific rationale for this therapeutic promise, many cytokine-related therapies have failed to establish clinical utility. In March 2009, international experts from academia, industry and government convened to discuss the scientific and clinical basis for the successes and failures of recombinant cytokines and cytokine antagonists as therapeutic agents, and possible strategies for improving their clinical success. This volume includes extended versions of key presentations at the meeting.