IL1B and atrial fibrillation: Bone marrow mesenchymal stem cell‐derived exosomes (BM‐MSCs) can activate the PI3K/AKT signalling pathway, thereby activating mTOR, inhibiting IL‐1β‐induced apoptosis, and the expression of inflammatory factors (IL‐6, COX‐2, and PGE2) induced by IL‐1β in AF cells.110