Challenge participants were provided with SNP data collected on 2,706 anti-TNF-treated RA patients6 (Supplementary Table 1) with which to develop predictive models of disease-modulating treatment response where treatment efficacy was measured using (a) the absolute change in disease activity score in 28 joints15 (DAS28) following 3–6 months of anti-TNF treatment and (b) categorical non-response as defined by EULAR-response criteria16. This evidence concerns the gene TNF and rheumatoid arthritis.