AHR and atrial fibrillation: We have previously described the impact of AF on apoptosis and associated signaling pathways.12,15 Others have shown the impact of AF on DNA binding mediated via the AhR transcription factor.51 However, we more recently determined that AF also directly impacts luminal breast CSCs and its actions against this cell population suggest a mechanism by which AF targets stemness to confer anticancer action in TamR BC cells.12,13 Gene expression analysis of MCF-7 mammospheres exposed to AF for 48 h showed a 2-fold induction in miRNA expression in mammospheres relative to control (Fig. 1I).