SYNPO2L and atrial fibrillation: Furthermore, the missense variant in SYNPO2L, rs3812629 (p.Pro707Leu), which confer risk to AF, was also found associated with MYOZ1 expression level in human atrial appendage tissue, and the median normalized expression level of MYOZ1 in homozygous risk allele GG carriers was -0.28 and extremely lower than in heterozygous GA carriers (0.94) (Figure 6B).