Martin et al. (2017) reported that NMN improves cardiac function and bioenergetics in a SIRT3-dependent manner in a Friedreich’s ataxia (FRDA) cardiomyopathy model, a mouse genetic cardiomyopathy model with frataxin-KO (Fxn–/–, FXN-KO). The gene discussed is FXN; the disease is cardiomyopathy.