Dr. Anthony Fauci, the U.S. scientist who helped lead the nation’s COVID-19 pandemic response, is set to face off — again — with a Republican senator probing the origins of the coronavirus. It’s part of Paul’s yearslong accusations that the now-retired infectious disease expert had lied about the pandemic, something Fauci has called “preposterous.” Leading up to the hearing, Paul released more than a thousand pages of Fauci’s personal diary covering the pandemic years. In an earlier letter to Paul, Fauci’s attorneys called his allegations “absolutely baseless” and part of an “obsessive and groundless vendetta.” Fauci has previously stressed he was using the risky experiment definition and that “it would be molecularly impossible” for those bat virus experiments to have turned into the pandemic virus.