This is in agreement with EPIC study, which reported the strongest risk related to current smoking of 34% for ER+/PR-, 23% for ER+/PR+, and 13% for ER−/PR-, [11] and American Retired women study which found 37% increased risk of ER+/PR- breast cancer in current smokers, and none with ER+/PR+ or ER−/PR- subtypes. The gene discussed is ESR1; the disease is breast cancer.