Hank Green, a popular YouTuber and best-selling author, shared a video on Friday saying he has Hodgkin’s lymphoma, a lymphatic system cancer. He said he was more likely to get the disease because he had taken some medicines, had an autoimmune disease, and had mononucleosis as a child. However, he stressed that he has “one of the most treatable” forms of cancer and that it was diagnosed at an early stage.

Even though he was positive for most of the video, he said he was processing the news personally in a “deeper, more emotional way” and would be too “heavy” to talk about how it affected his personal life in public. Green said he doesn’t have any symptoms, but he expects that chemotherapy will make it hard for him to keep making films. “I’m playing it by ear,” he said. “I know that I’m going to feel like garbage.” The “go-to science guy” got some love on Twitter from VidCon, a yearly event for creators that Green helped start. Green asked his fans to send him ideas for movies, TV shows, video games (but not bad ones), and pictures of pelicans.