Gene expression can be regulated by the action of nuclear receptor proteins called peroxisome proliferator-activated receptors (PPARs). These function as transcription factors. They regulate cellular differentiation, nutrient metabolism and tumorigenesis. Three kinds of PPARs have been identified- PPARα, PPARβ/δ and PPARγ. PPARα is a nuclear receptor protein, which is important for the regulation of lipid metabolism in the liver. It is necessary for ketogenesis and is activated during a state of energy deprivation. By altering gene expression of a large number of target genes it influences biological processes. PPARδ is a nuclear hormone receptor, which may be involved in the pathogenesis of several chronic disease conditions, such as obesity, diabetes, atherosclerosis and cancer. PPARγ may be expressed in three distinct forms- PPARγ1, PPARγ2 and PPARγ3. It is responsible for the storage of fatty acid and glucose metabolism. This book is a valuable compilation of topics, ranging from the basic to the most complex advancements in the understanding of peroxisome proliferator-activated receptors. It presents this complex subject in the most comprehensible and easy to understand language. Coherent flow of topics, student-friendly language and extensive use of examples make this book an invaluable source of knowledge.