VIP and atrial fibrillation: GSEA revealed that the set of KEGG genes mainly associated with VIP in AF was those involved in oxidative phosphorylation, cardiac muscle contraction, and neuroactive ligand–receptor interaction (Figure 5(b)); and the GO genes that were primarily associated with VIP were those involved in the regulation of oxidative stress-induced neuron death, cardiac myofibril assembly, and cardiac muscle cell action potential (Supplementary Figure 4B).