NOD2 and Blau syndrome: Studies targeting the NOD2 gene have identified mutations of NOD2 in sarcoidosis, sarcoid-related uveitis, and orofacial granulomatosis, including those associated with Blau syndrome, suggesting that NOD2-related pathways could play an important role in basal predisposition to the risk of occurrence of uncommon forms of sarcoidosis [87,88,89].