Book excerpt: The purpose of this book is to examine immune-to-brain communication from the viewpoint of its effect on pain processing, and to clarify the major role that substances released by immune cells play in pain modulation. In these chapters, contributed by major laboratories whose focus is understanding how cytokines modulate pain, the perspectives examined range from evolutionary approaches across diverse species, to the basics of the immune response, to the effect of cytokines on peripheral and central nervous system sites, to therapeutic potential in humans. -- book cover.