HIF-1 complex activation has neuroprotective effects in both in vitro and in vivo PD models, and the underlying mechanisms appear to be related to HIF-1-mediated expression of the erythropoetin (EPO) and vascular endothelial growth (VEGF) genes (Figure 2; Schofield and Ratcliffe, 2004; Semenza, 2014; Strowitzki et al., 2019). The gene discussed is VEGFA; the disease is Parkinson disease.