PROJECT SUMMARY Despite high enrollment in medical school and graduate programs, women remain under-represented in the biomedical research workforce. NIH T32 training programs are an understudied yet important contributor to the biomedical research workforce and are a key stage at which we can intervene. While roughly half of trainees covered by T32 grants are women, women remain underrepresented amongst those earning extramural research support. Given its prevalence in both medicine and science, sexual harassment is likely a contributor to this disparity. Data from the National Academies of Sciences, Engineering, and Medicine describe the damage caused by sexual harassment, ultimately leading to a costly loss of talent as women, particularly women with intersectional identities, and sexual and gender minorities leave. The drivers of sexual harassment, including factors and conditions that allow it to thrive, have been described with a conceptual model incorporating an iceberg as a metaphor. The vast majority of sexual harassment, this model contends, is the portion of the iceberg that is invisible under water. Because of this, many do not fully perceive the prevalence of sexual harassment; however, the behaviors described in this model are damaging whether they are visible (i.e., above water) or not. Despite these data, it is not yet clear what interventions can effectively decrease the occurrence of sexual harassment. Newer interventions, such as civility and upstander interventions, have been recommended by the Equal Employment Opportunity Commission but have not been rigorously tested. Data suggest that interventions that go beyond sexual harassment alone and address other related issues, such civility and upstander interventions, may be more effective than sexual harassment training alone. We will conduct a randomized, controlled trial of NIH T32 programs to test whether a multi- modal virtual intervention incorporating video game elements can increase T32 Principal Investigators’ and mentors’ confidence in their ability to intervene when they hear about or see sexual harassment and increase their knowledge on these topics. Furthermore, we will test the impact of the intervention on their mentees’ experiences with microaggressions and sexual harassment, sense of belonging, well-being, research productivity, and persistence in a biomedical research career. Finally, we will test whether the intervention improves the culture and climate of the learning environment. Rigorous evaluation of a virtual interactive intervention to address and reduce sexual harassment for NIH T32 trainees can result in a generalizable and easily scalable educational program to improve NIH training environments nationwide and ultimately improve the diversity of the biomedical research workforce.