Studies have shown that the loss of CP and subsequent iron accumulation in the SN, MPTP-induced PD mouse model, and 6-OHDA injured mouse model of PD patients exacerbate the death of DA neurons in PD (Youdim and Riederer, 1993; Friedrich et al., 2021; Ayton et al., 2013; You et al., 2015; Wang J. et al., 2015a). The gene discussed is CP; the disease is Parkinson disease.