In conclusion, this study demonstrates that the MEFV M694V (rs61752717) SNP markedly increases the risk of AS even in patients not suffering from FMF, and is associated with increased serum IL-1β levels in those patients, suggesting that IL-1 inhibition may be effective in that subset of AS patients, and that MEFV-driven autoinflammation is a factor in the aetiopathogenesis of AS. This evidence concerns the gene MEFV and familial Mediterranean fever.