When SOX4 and Gln71* were co-transfected (simulating the pathological condition of an AF patient with a heterozygous SOX4 mutation of Gln71*), the induced transcriptional activity on the GJA1 promoter was ~5-fold (SOX4 versus Gln71* + SOX4: t = 6.6464; p = 0.0027). This evidence concerns the gene GJA1 and atrial fibrillation.