FGF21 and diabetes mellitus: Our previous study also showed that the renal protective effect of FF in diabetes is FGF21-dependent, and here we have further confirmed that FGF21 is upstream of the Akt2/GSK-3β/Fyn/Nrf2 pathway, as illustrated in Figure 8, because deletion of Akt2 in vitro (Figure 4F) and in vivo (Figure 5G) does not affect FF-induced FGF21 expression.