TNFSF12 and atrial fibrillation: Atrial myocyte hypertrophy can lead to conduction heterogeneity and is one of the most important substrates in AF.16, 17 TWEAK/Fn14 axis is a positive regulator of cardiac hypertrophy in cardiomyopathy.6, 9 The present study focused on the potential role and mechanism of Fn14 in TWEAK‐induced atrial myocyte hypertrophy.