Its immunogenicity risk is low.131 Decreases in neutrophil counts in patients taking TCZ do not appear to be associated with serious infections.132 Sirukumab, a human monoclonal antibody binding to the IL-6 with high affinity, also shows satisfied outcome with an expected safety profile in clinical phase 3 study.133 It provides another valuable chance to explore the effect of cytokine inhibition in RA rather than cytokine receptor inhibition. The gene discussed is IL6; the disease is rheumatoid arthritis.