PROJECT SUMMARY/ABSTRACT Reducing Inequities by Promoting Participatory Learning Experiences in Science (RIPPLES) is proposed by the Science Education Partnership (SEP) at Fred Hutchinson Cancer Center (Fred Hutch) in Seattle, Washington. The RIPPLES program meets the goals of the National Institutes of Health (NIH) and the Science Education Partnership Award (SEPA) to encourage students, particularly those from underrepresented groups, to pursue further studies in science, technology, engineering, and mathematics, diversify the scientific workforce, and advance the field of health disparities research. It aims to build understanding of the mechanisms of health disparities among secondary students, so that they are inspired and empowered to work towards healthy futures for all. 1) Curriculum development: RIPPLES engages secondary school students in fundamental biological concepts including mutation, human variation, and evolution through two units centered on health disparities, designed for the Next Generation Science Standards at the high school and middle school levels. The units, comprising 8-10 lessons that span 2-3 weeks, will examine the scientific, environmental, and social contexts for health disparities, emphasizing the social and structural determinants of health. RIPPLES also develops lesson modules using real-world data that engage students in building quantitative skills as they analyze the factors that contribute to health disparities. Once developed, we will evaluate the efficacy of the curricular materials using a well-matched comparison group study. 2) Teacher professional learning: RIPPLES enhances the ability and confidence of secondary school life science teachers to teach fundamental biological principles and practices through the lens of health disparities by providing 20 teachers annually with a three-week summer professional development program that includes a mentored research experience, and seven additional day-long sessions throughout the school year (three orientation and follow-up, and four content workshops). 3) Student programs: RIPPLES aims to inspire and empower secondary school students, particularly those from underrepresented groups, to become the next generation of scientists, changemakers, and community health leaders. A two-week summer program designed for American Indian/Alaska Native youth introduces students to science research and community health using culturally relevant approaches and mentoring from scientists and students close in age to participants (near-peers). In addition, an event hosted at Fred Hutch and open to all students will celebrate student community action-oriented projects and connect youth with professionals, community members, and other students.