SNCA and Parkinson disease: To investigate how H3K4 me3 regulates α-synuclein expression, a CRISPR/dCas9-based locus-specific H3K4 me3 demethylating vector was established to reduce H3K4 me3 at SNCA promoter and was shown to decrease mRNA and protein expression of α-synuclein, both in the SH-SY5Y cells of neuronal cell line and dopaminergic neurons derived induced pluripotent stem cells (iPSC) of patients with PD (Guhathakurta et al., 2021).