四五运动
During Mao Zedong's final years, Mao Yuanxin had a close relationship with the Gang of Four. Some historians believe that Mao Yuanxin relayed news to Mao that the April 1976 "Tiananmen Incident" was planned by Deng Xiaoping, which resulted in Mao's final break with Deng before the latter's purge. He was arrested along with other of their supporters following Mao's death in October 1976, and was sentenced to seventeen years in prison by court martial.