When Watson and Crick proposed the double helix model for DNA structure in a 2 page Nature article in 1953, no one could have predicted the enormous impact this finding would have on the study of human disease. Over the last decade in particular, major advances have been made in our understanding of both normal biological processes and basic molecular mechanisms underlying a variety of medical diseases. Knowledge obtained from basic cellular, molecular and genetic studies has enabled the development of strategies for the modification, prevention and potential cure of human diseases. This brief overview focuses on the enormous impact molecular studies have had on various aspects of medicine. The inherited cardiac disorder hypertrophic cardiomyopathy is used here as a model to illustrate how molecular studies have not only redefined 'gold standards' for diagnosis, but have also influenced management approaches, increased our understanding of fundamental disease-causing mechanisms and identified potential targets for therapeutic intervention. The near-completion of the Human Genome Project, which identifies the 3.2 billion base pairs that comprise the human genome (the so-called 'Book of Life'), has exponentially heightened the focus on the importance of molecular studies and how such studies will impact on various aspects of medicine in the 21st century.