We also hypothesized that the Vj gating-induced changes in gj of the heterotypic Cx43/Cx45 GJs could affect the spread of excitation under various pathological conditions, mainly re-entrant-type arrhythmias, to which the AV node is known to be susceptible due to the existence of two distinct conduction pathways19. The gene discussed is GJA1; the disease is cardiac arrhythmia.