NR4A1 and breast cancer: Unsupervised hierarchical clustering of LowHR and TCGA samples based on DNA methylation profiles revealed four distinct clusters (Fig. 1a), mainly representing normal breast tissue (“Normal Cluster”), hormone receptor positive breast cancers (“HR+ Cluster 1” and “HR+ Cluster 2”) as well as TNBCs (“TNBC Cluster”) with little overlap between the different groups.