Interferons are produced by a variety of cells, primarily in response to viral infection. For instance, Type I interferons (IFN-α and IFN-β) are produced by almost all cells upon the detection of viral RNA or DNA. Type II interferon (IFN-γ) is mainly produced by natural killer and T cells. These interferons then bind to their specific receptors on neighboring cells, triggering a signaling cascade that results in the transcription of interferon-stimulated genes (ISGs).
