Although it is known to lead to the accumulation of IL-6 in the serum of treated patients (2), TCZ reduces the serum levels of pro-inflammatory cytokines [e.g., RANKL, MIF, chemerin, IL-21 (9, 10)], reduces CRP and SAA levels, and ameliorates the systemic manifestation of RA, such as pain, fatigue, and anemia (1, 2, 10). This evidence concerns the gene IL6 and rheumatoid arthritis.