Interferons α, β and γ are cytokines produced and secreted by animal cells after infection by viruses. Which one of the following statements about interferons is INCORRECT?
1
When mammalian cells are incubated with different interferons, activation of STATs (Signal Transducers and Activators of Transcription) links stimulation of cell surface receptors with gene expression.
2
Increase in the expression of genes after addition of IFNα results only after activation of the interferon‐stimulated response element (ISRE).
3
The receptors of all three interferons belong to the Ig superfamily of receptors and do not lead to downstream phosphorylation events.
4
An important feature of interferon‐STAT signaling pathway is its specificity: each type of interferon induces transcription of a unique subset of genes.