This is about gain-of-function research that the USA stopped in 2014 for safety reasons.<p>Gain-of-function is adding features to viruses. A goal of her research was to add functionality to coronaviruses that could infect humans. With funding stopped in the USA, she moved to Wuhan to continue her work.<p>The timeline runs for years, right up to December 2019. It includes a SARS coronavirus escape in 2017 that was caused when lab workers failed to properly inactivate the virus before taking it out of the BSL-4 high-containment facility.