In Genovese’s trial, all patients (391) were previously treated with one TNF-α blocker.25 These data lacked in Moreland et al’s trial.9 Concerning rituximab, 769 patients (of the 1143) received previously a TNF blocker.22, 23 It is possible that these patients were not at high risk of serious infection (we suppose that patients previously treated with TNF blockers were screened twice and that those who had a serious infection during the TNF blocker treatment were not included in another trial evaluating a biological agent). This evidence concerns the gene TNF and infection.