SOX4 and atrial fibrillation: Furthermore, a Sanger sequencing assay of the complete coding region of the SOX4 gene was executed in all the study subjects using the oligonucleotide primers given in Table 4, which uncovered that the mutation of NM_003107.3: c.211C>T; p.(Gln71*) in SOX4 existed in all the AF-affected family members but in none of the healthy family members as well as the 278 unrelated control subjects.