NLRC4 and macrophage activation syndrome: These are hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) mostly triggered by viral infections, rheumatological diseases and inherited lymphoid immune cell dysregulation [197,198,199] or a gain-of-function mutation in the inflammasome component gene NLRC4 [200]; and in the era of T cell immunotherapies, HLH and MAS are also initiated via BiTE [201] and CAR T cell therapy [181].