Breast cancer (BC) mortality for African-American women in the U.S. is 40% higher than for non-Hispanic white (Caucasian) women, despite the same incidence rate. Local epidemiologic data from Chicago similarly reveal a 4-5 fold greater risk of BC death among African-American women with tumors that express the estrogen receptor (ER) compared to Caucasian women with the same subtype of disease. This strongly suggests that biologic mechanisms are operating in ER positive (ER+) breast tumors arising in African-American women that arm those tumors with a more aggressive phenotype. Our lab aims to elucidate these mechanisms using metabolomics, transcriptomics and cistromics approaches.