Former President Joe Biden has been diagnosed with stage four prostate cancer, and it has reportedly spread to his bones. Experts say stage four is the deadliest stage for the illness, but they also say new advances in research and treatment for prostate cancer are changing outcomes.

On May 18, former President Joe Biden’s staff announced he has an aggressive form of prostate cancer. In response, several social media users began circulating a three-year-old video clip of Biden as evidence that he knew about his diagnosis years before.