Inflammation, in its broadest sense, is a host response to tissue injury. The four ancient, cardinal, signs of inflammation are redness, heat, swelling, and pain. These clinical signs of inflammation are, of course, the macroscopic culmination of molecular and cellular processes, many of which have become well defined over the last 120 years, and many of which may be reproduced in convenient experimental systems in vitro. In collecting the chapters for this section of the book, our aim is to provide a repository for experimental protocols for the in vitro study of key stages of the inflammatory response. For the reader who is unfamiliar with the field of inflammation, it is perhaps helpful to summarize and contextualize some of the key events of the inflammatory response, as it is these that may be reproduced in the form of in vitro model systems by using the protocols that follow.