Moreover, it was demonstrated that the hypomethylated status, a single region of the IL-6, may contribute to elevated serum levels of this cytokine, implying a role in the pathogenesis of these diseases [34], while the anti-inflammatory cytokines in the GCF, such as IL-4 and IL-10, showed no consensus among studies regarding the differences observed among individuals with PD and RA [43]. Here, IL6 is linked to rheumatoid arthritis.