FGF21 and type 2 diabetes mellitus: Additionally, diabetic cardiomyopathy in T2D is a putative target for FGF21, based on the fact that its receptor (FGFR1) and co-receptor β-klotho (KLB), which together confer specific responsiveness to FGF21 signaling, are expressed in primary rat cardiomyocytes as well as in rodent and human hearts [15,16,17,18].