Dane, 53, who played fan-favorite plastic surgeon Mark Sloan on Grey’s Anatomy, announced in April that he was diagnosed with ALS, an incurable neurodegenerative disorder. He’s spoken openly about the condition since, and even played a patient with ALS on a November episode of NBC’s Brilliant Minds. His former Grey’s Anatomy co-star Dempsey, who played top neurosurgeon Derek Shepherd, has now opened up about staying in touch with Dane amid the ALS diagnosis. I think he’s been incredibly courageous in the face of this horrible disease,” Dempsey continued. He also called the ALS diagnosis “heartbreaking” for Dane and his loved ones.