Table 1.

Quick guide to incorporating sex (and gender) as a biological variable

	Basic Research	Clinical Research
Literature	Perform quick literature search on sex difference research in your area and understand limitations therein.	Perform quick literature search on sex/gender difference research from clinical groups in your area and understand limitations therein.
Sample	Use both male and female cells, animals, and humans unless scientifically justifiable not to.	Enroll both women and men unless there is a sound scientifical justification not to.
Enrollment (for human studies)	Ensure recruitment strategies address barriers that may preclude participation of one sex vs. another.	Work with the clinical team to ensure recruitment strategies address barriers that may preclude participation of one sex/gender vs. another.
Data collection	Collect data from similar number of male and female subjects. Consider collecting data on variables that would influence sex differences.	Monitor data collection for sex/gender balance so enrollment strategies can be pivoted (population dependent). Consider collecting data on confounding factors that would influence sex/gender differences.
Data analysis	Break out male vs. female data to check for any differences.	Use design-appropriate statistical approaches to make sex/gender comparisons.
Reporting	Report number of male/female animals/subjects and any sex differences. Consider confounding variables and biological plausibility of any sex differences.	Report number of male/female subjects and any sex/gender differences. Consider moving beyond reporting sex/gender and integrating sex/gender into primary aims.