Of interest is also that variants of several regulated genes in both PDearly and PDlate samples, including GSTT1 (Wang et al., 2014), CXCR4 (Bonham et al., 2018), BAG3 (Cao et al., 2017) and HLA-DRB1 (Hollenbach et al., 2019), were previously associated with PD. This evidence concerns the gene CXCR4 and Parkinson disease.