Experiments have demonstrated that FGF-21 ameliorates dopaminergic neuron loss and α-synuclein pathological abnormalities in vivo and in vitro models of PD, and the SIRT1-autophagy axis plays an essential role in FGF-21 induced α-synuclein clearance (Chen et al., 2020). This evidence concerns the gene FGF21 and Parkinson disease.