By analyzing bulk and single-cell RNA-sequencing datasets generated from left atrial appendages of individuals with atrial fibrillation and non-affected controls, Leblanc and Yiu identify cell-type-specific genes and transcriptomic programs implicated in atrial fibrillation, a cardiomyocyte-specific androgen receptor signaling signature and an anti-fibrotic effect of NR4A1 inhibition in atrial cardiofibroblasts. This evidence concerns the gene AR and atrial fibrillation.