The new edition provides practical and timely information for toxicologic pathologists working in drug discovery and development. The introductory concept chapters are consolidated into two more concise and better organized introductory chapters. The two concept chapters introduce the reader to pharmaceutical R&D, the role of the pathologist in the process, and critical partner scientific disciplines with whom the pathologist will collaborate. In this revision, the organ system chapters incorporate more consistent commentary and guidance on the molecular mechanism of action, human translational relevance, and regulatory impact of pathological findings as they are described in these chapters. Key Features * Aids scientists in understanding spontaneously-occurring and compound-related pathological findings * Features three new well respected scientists on the editorial team * Consolidated 10 introductory chapters into 2 more concise and better organized concept chapters * Includes more consistent commentary and guidance in the organ system chapters