MFN1 and Parkinson disease: Environmental toxicants can cause PD by disrupting mitochondrial function or dynamics (Arya et al., 2018; Khater et al., 2021; Yin et al., 2021; Lin et al., 2022) regulated by Mfn1, Mfn2, and Drp1 genes (Gassner et al., 1997; Reddy et al., 2011).