LRRK2 and Crohn disease: In particular, a genomewide association studies (GWAS) demonstrated association of a single nucleotide polymorphism (SNP) of leucine-rich repeat kinase 2 (LRRK2) (park8) with both sporadic PD [7, 8] and other inflammation-related disorders such as Crohn's disease [9] and leprosy [10], establishing a new concept that neuroinflammation may play a primary role in neurodegeneration in PD.