Moreover, several studies propose a range of rare gene involvement (including GJA1, GJA5, KCNQ1, LMNA, NUP155, JPH2, SYNE2, and GREM2) associated with ionic channels, calcium-handling protein, fibrosis, conduction, and inflammation, in AF pathogenesis [20,21]. The gene discussed is GJA1; the disease is atrial fibrillation.