Subsequent studies2 examined the association between the common variant (SNP) rs76904798 (chr12:40220632:C:T) with LRRK2 RNA expression and found that the minor allele (T) was associated with increased expression levels of LRRK2. Like most of neurodegenerative diseases, PD is a complex disorder with several, and sometimes independently interconnected, pathways encompassing multiple proteins contributing to disease pathogenesis. This evidence concerns the gene LRRK2 and neurodegenerative disease.