Our former intern Emily Waltz points out that Scientific American’s March issue has given Francis Collins and Anna Barker, who lead the Cancer Genome Atlas initiative, several pages to, as Emily puts it, “make their case” for the project.

The cancer genome atlas, which is supposed to catalog all the mutations found in human cancers, is ambitious in scope—it’s expected to cost about $1 billion over the next decade. Just the pilot phase, which began a year ago, has a tab of $100 million. That’s no small sum when individual researchers are feeling the pinch of tightening budgets.

Emily is understandbly skeptical. Her reporting of the project last year uncovered serious practical hurdles facing the project, including the lack of enough tumor samples with the required informed consent. Privately, many scientists also complain that this is a vanity project and is unlikely to do much beyond run up masses of data.

As if in direct response to that criticism, Collins and Barker say, “Piles of data are, of course, not worth much without evidence that comprehensive knowledge of cancer’s molecular origins can actually make a difference in the care of people.”

Collins and Barker are right to note that drugs like Gleevec, which is what scientists like to call a “rational drug,” can result from identifying the molecular origins of a cancer. But the article isn’t really clear on how the project is likely to deliver those drugs—at least, not enough to make it worth the hefty price tag.