“I have cancer,” he wrote. “It sucks and I’m scared, and at the same time I’m blessed with incredible doctors and family and friends to get me through this.”
During a Twitch livestream in July 2021, Mark shared that he had been diagnosed with stage 4 diffuse large B-cell lymphoma. “My cancer’s not bone-related, it’s blood-related,” he said in a clip that was shared by the YouTube account Blink-182 Chile. “My blood’s trying to kill me.”
He expanded further upon the mental and physical toll his illness took on him in a December 2021 interview with GQ.
“I had a really dark time after finding out,” he shared. “I went through this whole period of like, not why me, but of course me. Why wouldn’t it be me? We’ve had so much good luck and good fortune, and things have kind of fallen into place for me specifically for so long, that of course I was due. I was due for something tragic.”
He described chemotherapy as “like being on the worst international, overnight flight where you can’t sleep or get comfortable,” but noted that he was able to find solace speaking with his mom, who had previously beaten the same type of cancer.
“She’s been my greatest resource this whole time,” he told the outlet. “Nobody knows what it’s like except somebody who’s gone through chemotherapy.”
:quality(85):upscale()/2026/05/08/930/n/1922564/39fc3a4769fe538bbbb7a7.21357619_.jpg "The Met Gala 2026 Theme, Exhibit, and More Details About Fashion's Biggest Night")