TH and Parkinson disease: Li et al. (2019) suggested that hsa-miR-7 regulates the BDNF axis in the early stages of PD and could serve as a biomarker for PD treatment (Li et al., 2019). Hsa-miR-218 is significantly up-regulated and regulates SLC6A3, TH, and EBF3, which may be involved in the pathogenesis of PD and therefore may be therapeutic strategies for PD (Li et al., 2018a). Hsa-miR-4639-5p is abnormally up-regulated and down-regulates PARK7, a well-known PD-related gene, further leading to severe oxidative stress and neuronal death (Chen et al., 2017).