Figure 3.

The effects of IFITM proteins on type I IFN signaling in cancer. In cancer, radiation and chemotherapy along with other sources of DNA damage are ultimately sensed by pattern recognition receptors (PRRs) that activate the type I IFN response. A chronic low level of type I IFN (blue box) promotes protumor effects, whereas acute high levels of type I IFN (red box) promote a protective immune response toward cancer. We propose a speculative model whereby IFITMs create a negative feedback loop to repress the effects of ongoing PPR stimulation and create a state of type I IFN resistance in cancer.