Molecular chaperones are a ubiquitous class of proteins that play important roles in protein folding and in the protection of cells from several stresses associated with the disruption of three native dimensional structures of proteins. The most important of these proteins are the so-called heat shock proteins (HSPs), also known as stress proteins. This book examines some of the biological aspects of this intriguing family of proteins that are important for consideration of the "proteiomics of HSPs". This book also reviews current research on protein folding in the endoplasmic reticulum (ER) and the functions of ER-resident molecular chaperones in protein folding in the ER. The biochemical, structural and functional information on Redox Enzyme Maturation Proteins (REMPs) are also reviewed in detail. Furthermore, recent progress in molecular biology has provided new insights into the molecular basis of diseases and molecular targets for diagnosis and therapy of human diseases. The role of molecular biology research in molecular imaging is examined, as well as the applications of molecular imaging in diagnostics, gene therapy and drug development. Other chapters in this book explore the role of protists as promising objects for the study of adaptive mechanisms at the biochemical and the molecular level, the different trends in the evolution of molecular adaptations to adverse environmental conditions, and a review of the molecular mechanisms of bicyclol in the protection against liver damage.