2023) in immune‐related PD risk loci (such as LRRK2, SNCA) (Li, Tan, and Yu 2014; Sliter et al. 2018). Although observational studies have suggested that immune dysregulation is involved in the pathogenesis of PD (Hirsch and Hunot 2009), establishing causal relationships between specific immune cell proteins and disease risk remains challenging due to confounding factors. Here, LRRK2 is linked to Parkinson disease.