NOD2 and Blau syndrome: These conditions include hereditary auto‐inflammatory syndromes associated with activating mutations in NOD2, such as early‐onset sarcoidosis and Blau syndrome, and early‐onset inflammatory bowel disease, in particular Crohn's disease where NOD2 signaling may play an important role (Kanazawa et al, 2005; Stronati et al, 2008; Negroni et al, 2009; Yao et al, 2011; Caruso et al, 2014; Uhlig & Schwerd, 2016).