The laboratory wing where Maraviroc was developed at Pfizer' [Getty Images]

UNITED KINGDOM - FEBRUARY 26: The laboratory wing where Maraviroc was developed at Pfizer's European Headquarters in Sandwich, U.K., Monday, Feb. 23, 2007. In 1996, scientists solved a mystery surrounding certain gay men who were immune to AIDS. This year, Pfizer Inc. will sell the first drug based on that discovery. (Photo by Suzanne Plunkett/Bloomberg via Getty Images)

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