I'm having some problem, I can't get the opinion to come up, so I haven't read it yet. Also, I know very little about patent law, so can't speak with much authority in this area.
That being said, so far as I can tell, it sounds like the decision is well-founded. My general understanding is that you cannot patent anything naturally occurring, as Taq said.
I can see policy reasons both ways. If a company cannot protect its work for some period of time, there's less an incentive to do the work. On the minus side, according the NY Times article, courts were issuing injunctions against research institutions based on the patent, and the public interest in allowing unfettered research into breast cancer is obvious.
Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus. -- Thomas Jefferson
For we know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus -- and non-believers. -- Barack Obama
We see monsters where science shows us windmills. -- Phat