The ECOG-ACRIN Cancer Research Group is a multidisciplinary, membership-based scientific organization that designs and conducts biomarker-driven cancer research involving adults who have or are at risk of developing cancer. ECOG-ACRIN comprises over 1400 member institutions in the United States and around the world. Approximately 21,000 physicians, translational scientists, and associated research professionals from the member institutions are involved in Group research, which is organized into three scientific programs: Cancer Control and Outcomes, Therapeutic Studies, and Biomarker Sciences. ECOG-ACRIN is supported primarily through National Cancer Institute research grant funding, but also receives funding from private sector organizations through philanthropy and collaborations.