LRRK2 and Crohn disease: Mutations in LRRK2 are causal for Parkinson’s disease (PD) (Paisan-Ruiz et al, 2004; Zimprich et al, 2004) and genetically associated with several inflammatory diseases including Crohn’s disease (CD) (Hui et al, 2018; Witoelar et al, 2017), leprosy (Fava et al, 2016; Wang et al, 2015) and systemic lupus erythematosus (SLE) (Zhang et al, 2017).