While our findings support that the decreased reticulum-driven mitochondrial Ca2+ uptake, consequently leading to reduced mitochondrial Ca2+ content, is an early trigger of mitochondrial dysfunctions in diabetic cardiomyopathy, an intriguing point is raised by the absence of a significant role for MCU in baseline cardiac function using an acute MCU-KO mouse [33]. Here, MCU is linked to diabetic cardiomyopathy.