LRRK2 and Parkinson disease: Interestingly, according to high LRRK2 expression in immune competent cells, genetic variations in the LRRK2 gene have been implicated in susceptibility to infectious agents such as Mycobacterium Leprae [15] and Mycobacterium Tuberculosis [16] and associated with inflammatory diseases including Systemic Lupus Erythematosus [17] and Inflammatory Bowel Disorders (IBD) [18]; patients with IBD have a higher increased risk of PD.