ESR1 and breast cancer: In another study, Krieger et al. utilize state-level policies as a measure of structural racism, finding that birthplace in a state with a history of Jim Crow ordinances was associated with an increased risk of estrogen receptor negative (ER−) breast cancer subtypes among black, but not white women.13 Krieger et al. selected ER− for attention, citing evidence that breast cancer subtype may be affected by early life, adolescent, and adult exposures.14