The FDA issued a warning letter to a Texas clinical researcher, claiming he deviated from his own investigational plan by enrolling ineligible trial subjects.

The FDA’s rules for clinical investigators cover a lot of ground, from how to avoid financial conflicts of interest, to delegating investigator authority to other members of the trial team, to hiring—and sometimes firing—investigators under your charge. The FDA provides all the GCP regulations and guidances you need to run a clinical trial, but even those documents can’t answer every question you may have about the people who actually conduct the trial.

The FDA ruled the use of mitochondrial replacement technology in clinical research is illegal.