Intriguingly, expression quantitative trait loci analysis revealed that AF risk variant carriers in the human population express significantly more, not less, TBX5 in the heart.14 It will be interesting to investigate whether the Tbx5-p.G125R TF and increased TBX5 dose in risk variant carriers share transcriptional responses underlying AF propensity. Here, TBX5 is linked to atrial fibrillation.