Younger age, shorter symptom duration or elevated C-reactive protein (CRP) values were found to be predictive of a Bath ankylosing spondylitis disease activity index (BASDAI)-50 response or an assessment of the SpondyloArthritis International Society (ASAS)-40 [5,7-9] response to TNF-blockers [5,10]. The gene discussed is CRP; the disease is ankylosing spondylitis.