President Obama’s ambitious precision medicine initiative faces some major obstacles requiring new scientific approaches, two researchers write in the latest issue of the journal Science.

The president has charged the National Institutes of Health with forming a cohort of 1 million Americans who will allow researchers to sequence their DNA and store it in a massive database to be used for research purposes. The project is aimed at furthering a relatively new medical field known as precision medicine, which provides targeted cures for individuals based on their genetic makeup.