TNF and systemic lupus erythematosus: The fact that neutrophils isolated from patients with active SLE – thus constitutively displaying the so-called IFN signature (Fig. 7a) – produce higher levels of both IL-6 and TNFα in response to R848 than HD neutrophils is consistent with the in vitro effects of IFNα on the same cytokines (Figs 1a and 3a).