MEFV and familial Mediterranean fever: Ever since this discovery, genetic testing has facilitated diagnosis in ambiguous cases and has widened the spectrum of clinical manifestations associated with disease.3 Moreover, the recognition of the PYRIN domain at the N terminus of pyrin in more than 20 human proteins involved in the regulation of inflammation ultimately led to the recognition of interleukin (IL)-1β as a central mediator of inflammation in FMF.4