Progesterone pretreatment is shown to reduce the incidence of drug-induced TdP in atrioventricular node-ablated isolated perfused rabbit hearts (Tisdale et al., 2019) and to protect against prolongation of action potential duration – APD (90) and triangulation associated with potassium channel inhibition (Tisdale et al., 2011). This evidence concerns the gene KCNA3 and torsades de pointes.