The overall goal of the WU-PE-CGS is to build a rigorous, scientific evidence base for approaches direct engagement of cancer patients and post-treatment cancer survivors as participants in cancer research. Our focus is on rare and understudied cancer populations with significant disparities including cholangiocarcinoma, multiple myeloma, and colorectal cancer under age 50. Participant engagement strategies are most effective when they are adapted and implemented in real-world settings in partnership with community and patient advocacy stakeholders.