Stone et al. identified, in thirty-one PAPA and PAPA-like subjects, a chronic elevation of serum IL-18, without any sign of MAS; this result may suggest a link between pyrin inflammasome activation, IL-18, and autoinflammation without susceptibility to MAS; this relationship may, thus, also explain why subjects with FMF may present with increased IL-18 levels [5]. Here, MEFV is linked to macrophage activation syndrome.