Breast cancer (BC) is one of the leading causes of cancer-related death for women in the US.1 While Black women have a slightly lower incidence rate of BC than White women, they are more frequently diagnosed with advanced disease and have a higher incidence of aggressive forms of BC, such as estrogen receptor (ER)–negative disease.2 These differences in BC stage at diagnosis and ER status contribute to racial disparities in BC outcomes. The gene discussed is ESR1; the disease is breast cancer.