PITX2 and atrial fibrillation: In coming years, we will therefore witness an explosion of studies unravelling the contribution of epigenetic mechanisms to AF associated substrates such as gene regulatory networks linking DNA methylation and/or histone modifications to transcriptional regulation of key AF-associated transcription factors such as PITX2, TBX5, and ZFHX3 among others, or complex lncRNA–microRNA–mRNAs gene regulatory networks impacting on the electrophysiological and structural remodelling substrates underlying AF.