There are a wide variety of professionals involved with any study, all of whom are vital to ensuring safety and success. The principal investigator – or PI – leads the trial and directs the team of doctors, nurses, and other healthcare workers, while the study coordinator manages day-to-day activities. (The study coordinator is the main contact for participants.) Importantly, an independent ethics committee (or Institutional Review Board – IRB) monitors the study to ensure participant protection rules are closely followed, and an independent Data and Safety Monitoring Board (DSMB) periodically reviews data to ensure participant safety and sometimes efficacy.