MEFV and familial Mediterranean fever: Additionally, a small number of patients with BD were found to be carriers of mutations in MEFV (encoding the pyrin protein that plays a key role in the inflammasome complex and whose mutations cause familial Mediterranean fever), and some had variants in genes encoding Toll-like receptors (TLR-4) of the innate immune system, further directing BD toward an autoinflammatory pathogenesis [29].