IL1B and familial Mediterranean fever: FMF patients during attacks had significantly higher RAC1 expression levels than patients between attacks or controlsNo difference in RAC1 expression levels between attack-free patients and healthy subjectsSignificantly higher IL-1β levels were detected in LPS-stimulated PBMCs of FMF patients during attacks compared to attack-free patients or controlsIL-6 levels were comparable in unstimulated PBMC culture supernatants of attack-free patients and controlsRAC1 inhibition reduced IL-1β levels but not IL-6