IFX, infliximab; IV, intravenously; ASAS, ASsessment in AS; AS, ankylosing spondylitis; BASDAI, Bath AS Disease Activity Index; BASFI, Bath AS Functional Index; GAP, global assessment of pain; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate. This evidence concerns the gene CRP and ankylosing spondylitis.