LRRK2 and Crohn disease: Leucine-rich repeat kinase 2 (LRRK2) has been linked by human genetics to Parkinson’s disease, Crohn’s disease, and leprosy (Hui et al., 2018; Kalogeropulou et al., 2022; Kluss et al., 2019; Paisán-Ruíz et al., 2004; Rocha et al., 2022; Taylor and Alessi, 2020; Wallings and Tansey, 2019; Zhang et al., 2009; Zhu et al., 2023; Zimprich et al., 2004).