SOX5 and atrial fibrillation: In addition, Seifert et al. [106] explored the correlation between the four SNPs previously implicated with AF and PR interval (rs11047543, rs3807989, rs13376333, and rs2200733) and the electrocardiographic P-wave morphology in 176 cases affected with AF, and found that two SNPs, including rs11047543 next to SOX5 and rs3807989 in the vicinity of CAV1/CAV2, were significantly associated with abnormal P-wave morphology, implying significant effect on atrial conduction properties.