While current clinical trials for cardiac regeneration using induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) employ immunosuppressive regimens used in heart transplants, the precise immunosuppressive regimen needed remains elusive. Now, researchers have identified optimized immunosuppressive strategies that allow transplanted iPSC-CMs to survive without immune rejection in non-human primates. These findings advance the clinical potential of regenerative therapies for severe heart failure, addressing a major challenge in translating stem cell science into effective human treatments.