The fact that Tnks2, but not Tnks1, abundantly expresses in adult zebrafish epicardium and myocardium together with highly conserved cardiac action potentials and contractile dynamics in zebrafish with humans over mice make zebrafish a compelling HF model for studying the pharmacotherapeutic potential of TNKS inhibition for prevention of IHF. The gene discussed is TNKS2; the disease is hydrops fetalis.