FGF21 and familial dilated cardiomyopathy: Indeed, previous study proved FGF21 strongly improved high-glucose (HG)-induced oxidative stress and fibrosis in primary mouse cardiomyocytes, and these protective effects of FGF21 were markedly weakened by genetic blockage of β-klotho (19), suggesting FGF21 ameliorates DCM may be mediated by its direct action on the heart.