Katherine Marie Heigl

In June 2010, Heigl starred in the Lionsgate comedy-thriller Killers, opposite Ashton Kutcher, and then starred in and produced the big-screen drama Life As We Know It, directed by Greg Berlanti, which revolved around a woman and a man whose respective best friends die in a car accident; following the tragedy, they are left to share in caring for the deceased's orphaned daughter. Heigl received $12 million for both films.
Whether or not Heigl would leave Grey's Anatomy remained to be seen for the bigger part of season six. However, on March 11, 2010, Heigl reportedly did not show up for work when she was supposed to, and she and Shonda Rhimes had apparently come to an agreement to release her from her contract immediately. Therefore, Heigl's last appearance on the January 21 episode of Grey's Anatomy is also her final appearance on the season. Heigl said that her departure was not about advancing her film career but that she wanted to focus more on her family.
In January 2012, Heigl stated in an interview that she has asked the producers of Grey's Anatomy if she could return to the show to wrap up Izzie's storyine: "I’ve told them I want to return,” she said. “I really, really, really want to see where Izzie is. I just want to know what happened to her and where she went and what she’s doing now. My idea is that she actually like figures it out, and finds some success and does really well in a different hospital. She was always floundering you know, and so she was always one step behind the eight ball and I want to see that girl take some power back." She also went on to say that she regrets leaving the show: "Oh yeah, sometimes, yeah. You miss it. I miss my friends. It was a great work environment ... and it becomes a family. I spent six years together with these people every day ... you grow up together, in a way," and again commented on the possibilty of Izzie returning to the show, "I always felt that if they wanted me to come back and sort of wrap up that storyline ... I want them to know that I'm down with it if they want me to, but I completely understand if it doesn't necessarily work ... They've got a lot of story lines going on there."