Molecular medicine is concerned with the study of molecular structures and mechanisms, identification of molecular and genetic errors of disease and the design of molecular interventions for correcting these. Such studies are aided by various physical, biological, bioinformatics, medical and chemical techniques. The molecular medicine perspective lays emphasis on cellular and molecular interventions for the management of disease. In molecular pathology, diseases are studied based on an examination of body fluids, tissues or organs. Various techniques, such as DNA microarray, quantitative polymerase chain reaction, multiplex PCR, in situ hybridization, DNA sequencing, in situ RNA sequencing, etc. are used in molecular pathology. Molecular diagnostics refers to a collection of techniques that analyze biomarkers in the genome and proteome, the genetic code of individuals and how cells express their genes as proteins. These allow the diagnosis and monitoring of diseases, detection of risks and formulation of individual-specific therapies. Molecular diagnostics are widely used in prenatal testing for chromosomal abnormalities, identification of infectious diseases, disease risk management, etc. This book discusses the fundamentals as well as modern approaches of molecular medicine. It consists of contributions made by international experts. The extensive content of this book provides the readers with a thorough understanding of the subject.