This in turn raises the question of how LRRK2 may modulate the response to more ubiquitous pathogens implicated in PD and IBD, such as gut microbiota (Houser and Tansey, 2017; Ni et al., 2017), periodontal microbes (Vavricka et al., 2013; Chen et al., 2017) or influenza virus (Sadasivan et al., 2017). This evidence concerns the gene LRRK2 and Parkinson disease.