NLRC4 and macrophage activation syndrome: Among the various known inflammasomopathies, NLRC4-AIDs distinguish themselves from NLRP3-associated Cyropyrin-associated periodic syndromes (CAPS) and Pyrin-related Familial Mediterranean Fever (FMF) by the occurrence of MAS, elevated IL-18 production and the manifestation of potentially lethal infantile enterocolitis in the AIFEC subset of NLRC4-AID patients (3, 31, 32).