This clear and succinct book focuses on the fundamentals of how cells respond to their changing environment. The main forms of cell signaling--paracrine signaling, the release of hormones, electrical signals, and direct cell-to-cell contact--is explained. Detailed illustrations and sidebars with additional information help explain and clarify these forms of cell communication. Finally, students will learn how the genetic information stored in each cell's DNA is used to direct these communication processes.