Variants in the LRRK2 gene are common in both CD and PD, and while the pathogenic mechanisms are not well-understood, like other PD genetic risk factors, LRRK2 is known to regulate inflammatory responses.99 Several CARD15/NOD2 SNPs are associated with CD and contribute to disease risk, age of onset, and pathological manifestations, with dysregulated NFκB activity as a possible mechanism. Here, LRRK2 is linked to Parkinson disease.