Prdm16 is an early regulator of cardiac metabolism. Assessing different mouse models for the PRDM16 associated cardiomyopathy reveals distinct cardiac phenotypes after mono or biallelic Prdm16 inactivation.9,10,31 Metabolism is differentially affected at early (Prdm16csp1/wt) and late pathology stages (Xmlc2Cre;Prdm16flox/flox, Mesp1Cre;Prdm16flox/flox).10,31