Yan Chen study compared IL-18 level in mild disease group and active disease group and concluded that the latter had significantly higher IL-18 levels.[17] The same conclusion was mentioned in Wang Liuqing study.[18] In Seong-Kyu Kim study, Sjögren syndrome disease activity index score was noted to be related with the mRNA expression level of IL-18 (R = 0.36, P = .04).[21] Besides, the positive correlation between serological parameters and IL-18 level was also observed. This evidence concerns the gene IL18 and Sjogren syndrome.