SIX2 and atrial fibrillation: Bulk RNA-seq of 54 KAFOs (19 AF samples; 18–34 weeks GA) showed expression of canonical developmental renal epithelial and nephron progenitor genes (PAX2, PAX8, LHX1 and JAG1), while lacking cap mesenchyme markers (SIX2, CITED1 and GDNF).