Further supporting that a marked reduction in Cx43 expression is needed to observe noticeable effects in arrhythmogenesis, programmed electrical stimulation resulted in ventricular arrhythmias only in Cx43Cre-ER(T)/fl animals treated with 4-OHT (having less than 95% of normal Cx43 expression 14 days after induction), but not in those treated with vehicle (50% of the normal Cx43 content) [391]. The gene discussed is GJA1; the disease is Ventricular arrhythmia.