It was opened in a "containment machine, " where a "pink oily substance" was found along with the letter, which contained threatening language over gun rights, the official said.

WSJ: Letters to Mayor Bloomberg Tested Positive for Ricin

In 2006 Pink released the single "Dear Mr President, " an open letter to George W. Bush criticizing some of his policies, on her album "I'm Not Dead".

CNN: The Spirit of Music: Is the protest over?

On Sept. 22, The Pink Sheet, a medical trade publication, reported the FDA had said that Pfizer received an "approvable letter" from the FDA. Such letters are not approvals but instead a kind of delay, saying that most of the data needed for approval are in but that additional steps need to be taken if the drug is to reach the market.

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