ESR1 and ductal breast carcinoma in situ: Therefore, we microdissected 25 samples to enrich for epithelial RNA from 17 patients (see Additional file 1 for representative epithelial lesions) separated into three groups: the control group of normal epithelia from nine patients undergoing RM and the paired diseased groups, which consisted of 16 samples from eight patients (eight samples of HN and eight samples of adjacent ER- and PR-positive DCIS (Table 1).