NUDT15 and neurodegenerative disease: We also observed that the DNA methylation levels of CpG_19 located in TSS1500 (promoter region) in NUDT15 were positively correlated with ROS and 8-OHdG, indicating that the low/no transcription or gene silencing of NUDT15 was associated with increased DNA damage and decreased genome stability, which was implicated in the initiation and progression of neurodegenerative diseases [55].