One of the longest-running cast members of 'Grey's Anatomy' has confirmed that he has left the equally long-running show.

Justin Chambers, who played Dr. Alex Karev, confirmed to Deadline on Friday that he has now quit 'Grey's Anatomy' for good. In his statement, Chambers explained that he hopes "to diversify my acting roles and career choices. And, as I turn 50 and am blessed with my remarkable, supportive wife and five wonderful children, now is that time."

In a tweet to her 1.7 million followers on Twitter yesterday afternoon, Ellen Pompeo - the show's lead - confirmed the news, retweeting an article from Vanity Fair about Chambers' shock exit.

As ever, the show goes on and while 'Grey's Anatomy' is heading into its sixteenth season with confirmation from ABC that the show is cleared until Season 17, with the likelihood being that it will keep going until the heat death of the entire universe, or until Ellen Pompeo quits.

Currently, 'Grey's Anatomy' is the longest-running medical TV series on television, and frequently tops ratings for ABC in the US and has a huge international following as well. Speaking at the TCA recently, ABC Entertainment President Karey Burke said that the show would continue "as long as Ellen is interested in playing Meredith Grey."

Chambers was one of the original cast members on the show, having appeared in the series' pilot, 'A Hard Day's Night', in 2005.