AMPD3 and diabetic cardiomyopathy: Together with a series of our studies on the roles of AMPD3 in dysregulated cardiac energetics and excessive production of reactive oxygen species in diabetic hearts (Igaki et al., 2021; Kouzu et al., 2015; Tatekoshi et al., 2018), the present findings provide insights into mechanisms contributing to the development of diabetic cardiomyopathy (Figure 6).