This Cooperative Agreement award from the National Cancer Institute (NCI) under the Cancer Cause and Prevention Research program (CFDA 93.393) is supporting the development of computational tools to accurately infer genetic ancestry from cancer-derived molecular data. The $457,549 award to Cold Spring Harbor Laboratory (CSHL) aims to enable large-scale analysis of cancer genomic data stored in repositories and archived tumor tissue samples, without requiring the patient's cancer-free genotype or self-reported race/ethnicity. The key products will be software tools capable of inferring global genetic ancestry at sub-continental resolution, ancestral admixtures, and local ancestry - optimized to perform consistently across varying profiling depths and qualities, and mitigate cancer-related genomic damage. The open-source tools will be made available to the research community through platforms like GitHub, Bioconductor, and Galaxy, along with training and outreach support. This award is expected to unlock vast amounts of existing cancer genomic data for ancestry-oriented studies, with the goal of better understanding the link between cancer biology, genetics, and patient ancestry.