Genome wide association studies (GWAS) for AF have identified single nucleotide polymorphisms (SNPs) in KCNN2 and KCNN3 that are highly associated with AF (Ellinor et al., 2010; Ellinor et al., 2012; Christophersen et al., 2017). The gene discussed is KCNN2; the disease is atrial fibrillation.