KNOCKED UP star Katherine Heigl has dismissed reports she is to quit GREY'S ANATOMY, insisting her Hollywood career comes second to her role in the hit TV show. The 29-year-old made her big-screen breakthrough in Judd Apatow's 2007 romantic comedy and has since been hailed by critics as the next Julia Roberts. It had been feared Heigl would abandon the medical drama in order to take advantage of her considerable film success, but she insists she's looking forward to returning to her TV role as Dr. Isobel Stevens and won't be leaving just yet. She says, "When I come back to Grey's, I am actually really excited. After nine months a year for four years, of course you're going to think, 'I want to be someone else for a while.' "I landed really good things and I did them in my breaks. It broke up the monotony of the character and I'm very, very grateful for opportunities. But Grey's is such a good cast. Everybody is amazing."