IL18 and arthritic joint disease: FMF is a group of recessive genetic diseases that manifest as chronic fever, rash, serositis, arthritis, etc. In 2015, two independent groups demonstrated that caspase-1 p10/p20 tetramers recruited and activated by pyrin can process pro-IL-1β and pro-IL-18 into their activated forms (IL-1β and IL-18).