Invokana has been subject to intense scrutiny and speculation because last year a similar drug, Forxiga (generic name dapagliflozin), developed by Bristol-Myers Squibb in partnership with AstraZeneca, was rejected by the FDA. The reason for the rejection was concern over liver damage and cancer risk, specifically breast cancer and bladder cancer.

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If pigs could be genetically modified to reduce the risk of organ rejection, it might be possible to use their organs for permanent transplants, not just temporary ones, many scientists believe.

CNN: Researchers clone pigs

Because these cells would essentially be clones made from the patient's own cells, there would be no risk of the rejection problems typical with organ transplants, and therefore no need for the drugs that prevent the immune system from attacking a transplanted organ.

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