Compared with the cells treated with 6-OHDA alone, the expression of TH and GPX4 did not decrease, and the expression of SNX5 did not increase in the cells treated with the combination of 6-OHDA and fer-1, indicating that the level of ferroptosis in the PD cells was inhibited by fer-1 (Figure 5(b)). This evidence concerns the gene TH and Parkinson disease.