This textbook emphasizes the application of the advanced scientific method to diagnose human diseases, to now acknowledge and discover the multifactorial aetiologies of diseases as well as factors affecting their progression. This multifactorial nature in most major diseases is ultimately the result of aberrant gene expression and individual susceptibility to a disease, influenced by patterns of gene expression in target cells or tissues for a particular type of pathology. These technical advancements in disease identification and reclassification acknowledge disease conditions based on the...