Thus, targeting myocardial metabolism in diabetic heart via BH4 could be beneficial, as we previously demonstrated in a cardiomyocyte‐specific Gch1 transgenic mouse, where augmentation of cardiomyocyte BH4 maintained cardiac function, glucose uptake and utilisation in diabetes (Carnicer Hijazo et al., 2021). Here, GCH1 is linked to diabetes mellitus.