ERBB2 and atrial fibrillation: Several studies have found that miR125b acts through the ErbB2/Her2 pathway to regulate cell survival, proliferation, migration, EMT, and drug resistance in BC32,34,66–68 Our data suggest that AF promotes the recruitment of AhR to the miR125b-2–3p promoter which negatively regulates ER and Her2 signaling and inhibits the expression of stemness genes to thwart migration, colony formation, and mammosphere formation in luminal A BC cells.