To identify luminal-specific circRNAs, we performed a DE analysis using the read counts provided by HashCirc. As shown in Figure 4A, we detected 113 DE circRNAs in ER+ versus TN tumors, 58 DE circRNAs in ER+ versus HER2+ tumors and, noteworthy, 622 DE circRNAs in ER+ versus NBO. Here, ESR1 is linked to chronic recurrent multifocal osteomyelitis.