IL1B and familial Mediterranean fever: It was also found that the levels of IL-1β (149.85±20.92 vs.55.5±37.5, P=0.0005), IL-18 (192±22.18 vs.102±57.4, P=0.0009), and IL-37 (78.19±14.3 vs.36.69±5.80, P<0.0001) in the untreated PBMCs of FMF patients were significantly higher than untreated healthy controls.