Until recently, hereditary tendencies toward multiple diseases, including cancer, were mainly determined by examining the family history of the affected individuals. However, the Human Genome Project has ushered in a genomics revolution and boosted the diagnostic testing industry with the emergence of genetic tests that may be used for the diagnosis and management of both inherited and noninherited malignancies. Genetic tests are already available to identify patients carrying cancer susceptibility genes and predict drug response, thus enabling physicians to carefully tailor a more personalized drug regimen that is more likely to result in a favorable outcome for the patient. However, before gene-based tests become widely available, thought leaders and society in general need to understand and discuss the major technical, ethical and economic ramifications of genetic testing. These issues are currently being reviewed by government, academia, regulatory agencies and professional societies using evidence-based principles.