At the end of the Iron Man 3,
Pepper Potts was infected with the Extremis Virus, which Tony then cured. As the scene is being narrated, he says something like, "Taking it one step further..." — before having doctors remove the shrapnel from his chest. This gives me the impression that the Extremis Virus is somehow related to him being able to remove the shrapnel from his chest.
Is this true?