The sequencing of the human genome opened a new world of biomarkers. Is it possible to tell by a person's genetic signature how they would respond to a particular drug? his is the dream of "personalized medicine". At the moment as many as half of all drugs do not work for the people who take them. Such pharmacogenomics could also reduce the size and cost of clinical tests by allowing pharma firms to select the most suitable patients. But the reality is rather different. The difficulty lies in proving that they reliably correlete with clinical outcome. Companies that had placed their faith in genomics are now caught in a dilemma: to produce information only or new drugs. As the cost of gene sequencing has fallen, firms have rushed to offer genetic tests directly to consumers, often raising grand expectations. There now seems to be a backlash. Doctors have complained about being bypassed. Most generic tests directly do not provide conclusive evidence of this risk of disease Some academics also remain deeply skeptical about genomics being used in medicine. In addition , personalised medicine would be economic folly for firms who would need to develop a special pill for every patient. Traditionally firms sold conventional one - size - all drugs. Perhaps a better way would be mass customization.