For this study, the development of congestive heart failure consecutive to toxic myocarditis [8] in a patient suffering from prostate cancer and undergoing enzalutamide treatment led us to study possible mutations in the mineralocorticoid receptor (MR) based on the improvement in heart function after removing enzalutamide and successful treatment with spironolactone. The gene discussed is NR3C2; the disease is Familial prostate cancer.