UCHL1 and Parkinson disease: Additionally, several genes are known to be associated with an increased risk of developing PD, such as the vacuolar protein sorting 35 homolog VPS35 (PARK17), the ubiquitin carboxyl-terminal esterase L1 UCH-L1 (PARK5), the translation initiation factor 4-gamma 1 EIF4G1 (PARK18), and beta-glucocerebrosidase (GBA) 90.