ESR1 and cancer: To determine whether NEP expression differed within tumor samples, we grouped samples by varying characteristics (ER/PR/HER2 expression and clinical subtype) and analyzed NEP expression levels across cancer stages using RNASeq data from the Cancer Browser database.42 We observed that NEP mRNA was significantly higher in stage I HER2-positive IDC than either stage II or stage III cancers (Figure 6b), but no significant differences were seen in other subgroups.