Although engraftment of exogenous EPCs has indirectly proved that FGF23 mediates protection against IR-AKI through EPCs, we admit that we did not have any way to mark and track the endogenous late EPCs accurately in our FGF23-overexpressing IR-AKI mice; the contribution of FGF23-mediated endogenous EPCs awaits further elucidation. Here, FGF23 is linked to acute kidney injury.