ESR1 and ductal breast carcinoma in situ: We observed no significant differences in ER expression (< 1%, 1%–10%, > 10%–50%, > 50%–100%) and PR expression (< 1%, 1%–20%, > 20%–50%, > 50%–100%) between luminal subtypes in “Pure” cases of high-grade DCIS and those “W/invasive” components.