NOD2 and Blau syndrome: To ascertain whether blocking IFN-γ signaling is a potential treatment for chronic inflammation in Blau syndrome patients, we still need to determine whether the IFN-γ pathway is actually activated in these patients and whether IFN-γ signaling is the principal priming pathway among the stimulants known to upregulate NOD2 expression (i.e., TNF-α, LPS, and other Toll-like receptor ligands) (55–57).