This invention provides methods, compositions, and kits relating to gene product biomarkers where gene expression levels are correlated with therapeutic response of rheumatoid arthritis patients to treatment with an IL-6 receptor antago nist, Such as an IL6-R antibody. The methods, compositions, and kits of the invention can be used to identify rheumatoid arthritis patients who are likely, or not likely, to respond to IL-6 receptor antagonist treatments.