Ellen Pompeo on 'Grey’s Anatomy' landmark episode, Ariana Grande video and Sandra Oh's emails - USA TODAY

Ellen Pompeo on 'Grey’s Anatomy' landmark episode, Ariana Grande video and Sandra Oh's emails  USA TODAY

Ellen Pompeo is most recognizable as Meredith Grey on “Grey's Anatomy" − and she knows how big a deal it is for people to still be watching, 15 seasons later, ...