DeFontes said the owner of the tooth had been made an offer from an unnamed European firm that had been interested in extracting DNA from the tooth for cloning but they were refused.

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Kristina Killgrove, an archaeologist at Vanderbilt University has been working with the skeletons of the common people of Rome, extracting their DNA to learn their stories.

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But scientists from three hospitals in Boston, USA, found that they could temporarily reverse the effects by extracting skin cells from patients whose DNA can't make factor VIII.

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