> ## Documentation Index
> Fetch the complete documentation index at: https://glossary.micahealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Principal investigator (PI)

The lead researcher who oversees and directs all aspects of the clinical study.

## Related terms

<CardGroup cols={3}>
  <Card title="Recruitment status" href="recruitment_status" />

  <Card title="Expanded access status" href="expanded_access_status" />
</CardGroup>

[*Source*](https://clinicaltrials.gov/study-basics/glossary)