Biological drugs, which have a complex structure, are far more complicated to produce than regular chemical drugs, which have a single molecular structure.

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And nothing is more so than the most complicated structure we know of in the universe, the human brain.

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Don Berwick, former administrator of the US Centers for Medicare and Medicaid Services, says the challenge ahead is much more complicated than merely tweaking Medicare's funding structure.

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In other years it could be much more than this and in some significantly less due to the complicated tax and allowances structure.

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