This hypothesis is supported by the observation that expression of Ttn, one of our candidate upstream regulators, is increased in atrial fibrillation patients with persistent disease (Deshmukh et al. 2015) and a recent GWAS that has for the first time identified the TTN locus as a susceptibility locus for atrial fibrillation in humans (Christophersen et al. 2017). Here, TTN is linked to atrial fibrillation.