Signaling pathways, such as Ang II/JAK/STAT3 [82], NF-κB [83], TNF-α [84], PI3K/Akt [85], and Wnt [86], are involved in key processes for the proper maintenance of cardiac metabolism and for the development and progression of AF, such as atrial remodeling, proinflammatory state, and fibrosis [87]. This evidence concerns the gene AGT and atrial fibrillation.