Mr McCluskey said he feared David Cameron could be elected on a message of "stick with us in difficult times", suggesting this was the successful approach used by President Obama last year.

BBC: Labour can't win on austerity agenda, says union boss

Every tumor has five to ten flawed genes driving its growth, and researchers may have to target several simultaneously with cocktails of drugs, the approach that worked against AIDS. But finding such cocktails will be slow and difficult because regulators frown on testing two experimental drugs together, and corporate rivals rarely share drugs.

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