Health Secretary Jeremy Hunt said the DNA mapping project was designed for medical research.
He told Sky News: "That will enable us to make groundbreaking discoveries about how cancer works; about who is susceptible to cancer; how we can head it off; what treatments might work."
"It's something that I hope will mean we can avoid heartache for thousands of people every year who lose a loved-one prematurely because they get a cancer that we simply don't know how to deal with."
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