ESR1 and breast cancer: In the present study, we screened a series of newly diagnosed invasive breast tumors from patients enrolled in the Carolina Breast Cancer Study (CBCS), a population-based case-control study of breast cancer in African American and white women in North Carolina, for the A908G point mutation in ER-α by using a combination of single-strand conformational polymorphism (SSCP) analysis and 33P-cycle DNA sequencing.