Figure 2

Activation of positive and negative feedback loops by interferons (IFNs). Low priming doses of IFNs will preferentially activate positive feedback loops, such as association with other receptors (not shown) and the induction of expression of IFN-stimulated genes that function as positive regulators of signaling, such as STAT1 and interferon-stimulated gene 15 (ISG15) (right). Higher doses of IFNs will also activate feedback inhibition, such as the induction of expression of suppressors of cytokine signaling (SOCS) (left). Jak, Janus kinase; STAT, signal transducer and activator of transcription.