Mutations in the NLRC4 inflammasome were found in patients with recurrent MAS [120], and patients with features of MAS and septic shock had mutations in the inflammasome NLRP3 and Mediterranean fever (MEFV) genes, leading to increased production of IL-1β and IL-18 by their monocytes in vitro [121]. Here, NLRC4 is linked to macrophage activation syndrome.