In the absence of PD-1 expression, both the immunoregulatory function of helminth-derived Ts-Cys on MI and ischemia/hypoxia-induced myocardial necrosis and inflammation were significantly reduced. In the absence of PD-1 expression, the immunoregulatory function of helminth-derived Ts-Cys on MI was significantly reduced, as were ischemia and hypoxia-induced myocardial necrosis and inflammation. The gene discussed is PDCD1; the disease is ischemia.