Priscilla Chan on meeting Mark Zuckerberg, and their goal to cure all diseases

Priscilla Chan – pediatrician, billionaire philanthropist, mother, and wife of Facebook founder and CEO Mark Zuckerberg – is on an ambitious mission to level the playing field for everyone. Chan and her husband have pledged 99 percent of their Facebook shares to the Chan Zuckerberg Initiative. Norah O’Donnell spoke with Chan about the initiative’s goals.