Moreover,in light of numerous pieces of evidence indicating increased LRRK2enzyme activity in LRRK2 mutation-related PD brains, we are eagerto investigate whether the LRRK2 distribution and expression in thebrain of PD patients could be visualized by PET imaging, which wouldin turn give rise to a more in-depth understanding of PD pathogenesis.To date, several LRRK2 inhibitors have been labeled with carbon-11or fluorine-18, which included GNE-102315 and its analogues16 as well as HG-10-102-01,17 but limited biological data were disclosed (Figure 1A). Here, LRRK2 is linked to Parkinson disease.