Regarding our findings of an association between levels of IL-6 and CD in RA patients, we recently published a systematic review article [40] on biomarkers of cognitive dysfunction in RA, and IL6, along with other cytokines (IL-2, IL-4 and tumor necrosis factor α),negatively correlated with memory and positively correlated with executive functions. This evidence concerns the gene TNF and rheumatoid arthritis.