FGF21 and atrial fibrillation: For example, an increase in coagulation-related proteins, such as fibrinogen, may lead to clot formation [30], whereas changes in inflammation-associated proteins, such as fibroblast growth factor 21 (FGF21) and macrophage inflammatory protein-1 alpha (MIP-1α), may be protective of the blood–brain barrier in the event of IS, or induce atrial fibrillation, which exacerbates inflammatory responses in brain tissue, as symptoms brought by condition [31, 32].