Dr. Anthony Fauci warned in a Senate hearing on Tuesday about the dangers of states reopening without following federal guidelines. Here's how he became the nation's top disease expert.

Dr. Anthony Fauci is one of the most influential figures in the nation when it comes to the coronavirus. As a member of the administration’s coronavirus task force, he often speaks at White House press briefings and has become a trusted expert on the virus. He also advises the president and vice president. His role as a top adviser for the government on health concerns has spanned six presidents.