TNF and cancer: • This comprehensive registry study has shown that (i) patients with rheumatoid arthritis treated with biological drugs are not at increased risk of invasive melanoma; (ii) patients with rheumatoid arthritis selected for TNF alpha inhibitors are not at increased overall risk for cancer but have an increased relative risk of invasive melanoma • The authors concluded that given the small increase in absolute risk, there is no shift in the overall risk-benefit balance of TNF alpha inhibitors in clinical practice; however care needs to be exercised in patients at high risk of melanoma